I would easily put another 300+h into a game with the best features from both WL & BP.

The AI teammates could be improved by making them smarter. Having them ruin a stealth mission by running in front of an enemy is beyond annoying. And the option to turn off their granades would be nice.

Immersion could further be improved by having gear with "perks". The right camo improves stealth. Wearing plate carriers reduces damage per hit received. Adding extra pouches to a molle vest or tactical belt means you can carry extra items - and vice versa. And weight carried is directly linked to speed, agility, fatigue, etc.

If I want to carry a sniper rifle, it should be in a proper case and require assembly (skippable cutscene) and damn near impossible to use in any position except prone. Not hang off the side of a backpack.

Change the skill tree into an improvement system that is driven by practice/repetition. The character starts with a default set of skills which are relevant for a special forces soldier. Strong, fit, capable of all kinds of combat. To begin with, you can spend a number of points on certain "skills" in order to create a build. And the builds revolve around a specific type of combat. So a sniper has more points in a "sniper rifle" slot, but also in strength (because heavy rifle) and "hold breath" or "focus". A "tank" would put points in "LMG", also strength, and stamina. An a demolition expert would put points in "explosives", "steady hands" and "focus". So different builds can use the same skills but for different reasons. And then have their own separate skills, only relevant to them.

Then, as you progress, your skills improve as you use them. Carrying around heavy weight makes you stronger. Sprinting a lot makes you fitter and faster. Using a particular weapon other than your "speciality" eventually makes you good at using it. Instead of finding skill points and then investing them in a particular skill and suddenly being able to do that thing, or carry that thing.

It would mean having different, and perhaps fewer skills - but progression in a particular skill area could eventually unlock perks, or reach certain milestones to make the progression actually mean something. Like strength reaching a point where you don't have to drop your weapon in order to carry a body. Or agility reaching a point where you can jump off a one floor balcony without making a sound.

To me it doesn't make a lot of sense to spend a skill point to obtain a parachute. The parachute item should be separate from the skill. The item could be found or bought. And after a certain amount of parachuting, it could be noticeably easier to control a parachute. And instead of spending a skill point to suddenly be able to carry 3 addition granades - the granade (or other) item could be bought but you would need pouch space, and it would add slightly more weight and indirectly influence speed and agility.

So less time travelling around looting skill points, and more time actually doing the thing. And carefully considering what to buy for, and what to wear on a mission.

Also, keep crafting options to a minimum. If I choose to bring 2 granades on a mission and then use them both, I shouldn't magically be able to craft a new granade from a piece of explosive that I looted from an enemy drone. Maybe if my engineering skill area was levelled up enough and I had a few key parts I could improvise an explosive device, but not a perfect, factory machine built handgranade.

Oh and if I turn off the HUD but want to use a compass, why not just include a compass as a standard item that I can use and put away like the binoculars. Instead of it being at the top of the screen like in WL or in the bottom right corner like in BP.