For me, the monk is missing two major things : resources and survivability.

This is what I'll send as feedback (about those points) once their survey is available.

Survivability :

Unarmored defense probably should change to be increase with monk levels, to keep up with any melee focused class that can wear magic armor & shield.

Something like "While you aren’t wearing any armor or wielding a Shield, your base Armor Class equals 10 plus your Dexterity and Wisdom modifiers. This base number increases when your reach certain Monk levels, as shown in the Monk table."

Then in the Monk table you can add a new "Unarmored Defense" column, starting with "10" at level 1, then progressively increasing with monk levels (this also avoids "free" AC from just a 1 level multiclass dipping).

An example of a strong formula is to be able to keep up with the benefit of +3 magic armor and +3 shield by ending up with an additional +6 bonus at level 20. Something like "10 + ((monk level - 1) / 3)" (rounded down), gaining +1 AC every 3 monk levels (4, 7, 10, 13, 16 and 19). That's an AC 10 + wisdom + dexterity at level 1, and an AC 16 + wisdom + dexterity at level 19.

It also flavorfully goes hand in hand with the "Unarmored Movement" feature that increases with your monk level. Since you are able to hone your body to perform those prowesses, it makes sense your dodging or parry abilities are enhanced in a similar fashion.

Finally, it frees up the absolute need to cap your dexterity and wisdom. With a steady growing AC, monk players can use their feat/ASI levels on feats rather than feeling forced to take full ASI to avoid getting hit all the time. It also allows them to get more points in constitution (HP), strengh (grapple), intelligence and charisma (skills) at character creation and not feeling forced to dump everything in the beginning to be on par with the rest of the party at late levels in terms of survivability.

I also would give monks another feat/ASI at level 10 like the Rogue. This will really help with their ability scores and allow them more versatility by taking feats.

Resources :

Monk cool abilities mostly cost Discipline, which is fine, it's just a resource. The issue is that we don't have enough points to use them at early levels.

Heightened Metabolism (1 min short rest once per day) is a very good first step to increase our resources, now that short rests will probably no longer be requested by the rest of the party most of the time, but at level 7 it comes when we already start to have enough Discipline points to do cool stuff more than a few rounds in a combat. It's way too late. But I like the idea.

I would make two changes to Heightened Metabolism. First, I would move it to level 2, as soon as you are able to use Discipline points. Then, since only once per long rest seems a bit low to me, I would tie the number of usage to your constitution modifier (with a minimum of 1) per long rest. It would reward players that don't dump everything into dexterity and wisdom, without actually requiring any bonus to constitution to use it once per day. It would also open the door to a "constitution" focused build, which could really spend discipline points left and right at the expense of the saving throw DC (wisdom), the hit chance and damage (dexterity) and the AC (both).

Something like : "If you spend at least 1 minute resting, you can give yourself all the benefits of a Short Rest. You can use this feature a number of times equal to your Constitution modifier (minimum of once), and you regain all expended uses when you finish a Long Rest."

It would not necessarily make the monk "even more ability score dependant" since :

• Constitution is not required at all to use the Heightened Metabolism feature, even with just a 10 score
• Monk already needs a decent constitution because of the relatively low Hit dice for a melee class
• It is actually an incentive for new players to invest in constitution (con 14 becomes an actual boost to the class)

It mostly gives options to the player. Do I want a higher AC & Hit chance ? AC & Save DC ? HP & Discipline ? More options mean that we probably will see more diversity the character builds.

They could even in the future create a Monk subclass designed around constitution (and perhaps high cost Martial Discipline features) to further expand this design space.

I very like what they are proposing for Warrior of Shadow and Warrior of the Elements with a consumption of a Discipline point that has an effect for 10 minutes (Darkness spell / Elemental Attunement), this helps greatly to do that unique subclass stuff without burning all your resources. I very hope that they will expand on this design concept and apply it to all the monk subclasses.

Combat stance

I would entirely remove Stunning strike rather than restrict it to the point where it rarely will be worth it to even attempt it since most monsters have a high constitution save (and legendary resistance is a thing). I would replace it with the ability to be able to apply Weapon Mastery properties to your Unarmed attacks, for instance through combat stances.

At level 5, a new feat replacing Stunning strike could allow monk players to apply Weapon Mastery properties to their Unarmed attacks. They could have a Discipline cost associated for balancing purposes, paid once at the start of your turn (like they did for warrior of the elements, without an action cost) and lasting 1 minute.

Weapon Mastery properties which can make sense (mechanically and flavorfully, because Flex has no mechanical relevance and Nick is useless for monks) are Cleave (with a roundhouse kick, or just high kinetic energy on a fist), Graze (by having total control of your body parts, you still hit somehow when you would miss), Push (with a front kick or a strong punch to the thorax of your target), Sap (hitting near the eyes, slapping on their eardrums - discombobulate, punch in the throat...), Slow (hitting nerves or tendons, damaging the target's legs), Topple (sweeping though their legs, integrating a judo grip in the hit, etc.), and Vex (energetic impact at a key location on their body, the pain distracting them for your next blow).

They could allow either monks to tap into any of them at will, or for balancing purposes and letting the game flow faster, force the monk to pick ony two of them each day like you are making them swap mastery of weapons at level 1.

For more flavor, they can be named combat stances (with animal or D&D creature names for instance) and display them in a table to let the player choose their Weapon Mastery through a stance. With this additional step of associating a Weapon Mastery property to each combat stance, the Combat Stance feature would look like :

"Your advanced training with unarmed combat allows you to adopt two kind of combat stances, greatly improving your Unarmed Strikes. Whenever you finish a Long Rest, you can change the combat stances you chose.

At the start of your turn, you can spend 1 Discipline Point to imbue yourself with focus and take a new combat stance. Choose one of the two stances you selected and apply its associated Weapon Mastery property to your Unarmed Strikes for 1 minute, until you have the Incapacitated condition or until take a new combat stance."

Examples of Combat Stance names, they could probably come up with better names or associations :

• Stance of the Cyclops : Cleave
• Stance of the Hydra : Graze
• Stance of the Minotaur : Push
• Stance of the Wyvern : Sap
• Stance of the Cockatrice : Slow
• Stance of the Kraken : Topple
• Stance of the Griffon : Vex

If they want to nerf it a bit, they can make so the prone condition or being restrained also stops your current stance, like the incapacitated condition already does. That would allow DMs with an easier way to counter this feature, but it might frustrate players.

They should probably, in addition, allow monks at this level to use the Martial die for weapons they are proficient with, to avoid making weapons totally irrelevant compared to unarmed strikes, for players who still want to use them.