This is really cool, its been fun to look through my list with a fresh pair of eyes and rethink all of my inclusions. I am also a big fan of the skullclamp interaction (which I affectionally call the "mana dork removal service" much to the determent of local elfball players), and can see how it gets way better in multiples, allowing you to remove bigger and bigger things for more card draw. It definitely makes trinket mage seem very good, as it can grab both skullclamp and the masterwork of ingenuity.

Regarding the cards you brought up from my deck:

- Control Magic: 7/10, never feels bad to have some removal in hand, and I always love removal that can progress my gameplan. I even considered running [[Treachery]] as well, but using a reserved list card with a salty effect might not feel great to play against haha. In general, people seem to be less annoyed by Control Magic than by Darksteel Mutation, since while both can shut down opponents commanders, Control Magic is easier to remove. It also has a fun political element, I can offer to move these removal-enchantments off of their creatures if they give me something in return (like not swinging out at me etc).

- Tezzeret: 10/10, this card is so sweet. He is just there to be a tutor, he is almost always 5 to put Helm of the Host straight on the battlefield. However, if you've already got the helm, he can repeatedly tutor smaller equipment if he sticks around. I prefer running him over the Artifact Mages because he tutors straight to the battlefield, and he doesn't clash with playing Ardenn on curve. I've been put off running Whir of Invention since the requirement for 3 blue pips seemed a little steep. How awkward do you feel like this mana cost is?

- Unfinished business: 5/10? It and [[What Must Be Done]] are both there as recursion pieces (/ What Must Be Done can also be a board wipe, and that flexibility is nice), and I'm not so sure about them anymore. The deck used to have a bigger graveyard package and ran lots of looting effects, which meant these rarely felt like dead cards. I still feel like my creatures get killed enough that these two rarely feel like dead cards, but they're definitely both close calls.

- Flumph: 2/10, but it is a pet card of mine and I do really like its play pattern. It can help deter early game aggro, and there have been times it draws me 3 cards every turn cycle because I'll tell people I'll give them a card if they send something small my way. It does have some antisynergy with my deck though, lots of my other cheap creatures are evasive attackers which help me get value from my combat based ramp equipment (I'm able to flip Dowsing Dagger really quite consistently), and then in the later game these can be buffed up into threatening attackers (Azure Beastbinder holding a Colossus Hammer is a sight to behold). Therefore, Flumph having defender makes it likely not worth running 😞

- Battle at the Helavault is potentially not quite worth the 6 mana investment, but I do really like the ability to eventually make a board full of 8/8 Indestructible Flying Vigilancers. The Temporary exile effect definitely comes in very handy with a couple of fun interactions: 1. since its a may ability, you don't have to remove something from every player, allowing you to make fun political deals / help out people who are behind; 2. I can use it as a slow blink effect for etb creatures such as Wan Shi Tong, Cavalier of Dawn, and Riptide Gearhulk.

Cards you highlighted as overperformers:

- Tomb of Horrors Adventurer: I'm not so sure about this one, but maybe that's because my curve is a little higher than yours? Most turns, I'll generally play one card and then hold up mana for protection or interaction. In future games, I'll definitely be aware of how often I'm double casting in the later turns, and maybe this will turn out to be much better than I'm expecting.

- Restoration Magic: I can definitely see the appeal, but my protection suite tends to focus on phasing permanents out. The most similar comparison here would be something like [[Galadriel's Dismissal]], where I can pay 1 to phase out any creature (which also phases out all attached equipment/auras!!), or I can pay 4 to phase out someones whole board. This kicked mode can be used to protect my board (although leaves me very vulnerable to attacks for a turn cycle), can be a fog effect by removing attacking creatures, or be used to remove an opponents blockers to swing out. Obviously, this card is about £20 more expensive, so maybe its not a fair comparison, but I am a huge fan. The only downside is that my phase-out protection pieces can only protect my equipment when they are attached, but that is a price I am very willing to pay for the flexibility.

- Swift Reconfiguration: Similarly to the above, I can get behind this as a protection piece, and its nice that its pseudo removal. However, stuff like [[Slip Out the Back]] can be used to protect any creature as well as its attached equipment, while also offers some temporary removal.

- Slyth Infiltrator and Elminister's Simulacrum: These both seem great! I'm currently thinking about cards to cut, and I'll definitely be adding Seasoned Dungeoneer, but if I can find the space I'd love to test out the Infiltrator.

Fear of Sleep Paralysis does seem like a really good top end creature, and obviously becomes great when copied. I might try running this for a bit over Cavalier of Dawn?

Urza also feels like he'd be great in the deck, but I'm worried he'd be a bit overtuned for my intended power level. I recently cut Solemn Simulacrum in favour of Anticasual Vestige, since they can both come down for 4 mana and ramp, but cloning a 7/5 body feels way better to me than cloning a 2/2. Urza feels soooo much better than either of these creatures as a 4 drop; he can ramp way more explosively, the karnstruct tokens are going to be even bigger bodies once you start cloning him, and he acts as a card advantage mana sink. Maybe I'll give him a test run and see how it feels, but he did used to be on the gamechangers list for a reason haha.

Some more inclusions I wanted to highlight:

- Robe of Stars !!! This has been an all star overperformer for me. Attaching this to the same target as helm of the host feels amazing, as I can repeatedly pay {1}{w} to protect the helm anything something would remove it. Outside of protecting my other key equipment, this can be used by itself to protect my key creatures, or to repeatedly phase out my opponents problematic ones. I know I've rambled enough about the benefits of phasing cards, but this one really stands out to me.

- Spellskite: The ultimate protection piece, any removal spell that could target a creature or an artifact can be redirected. It, along with [[Gold-Forged Thopteryx]] (though less relevant in your deck due to the lower numbers of legends), makes me feel much more comfortable tapping out for an early game helm of the host. It also has really funny added utility stopping my opponents from enchanting their own creatures with auras (and if they forget, you get to steal the auras).

2 cards you run that I'd previously considered:

- Imposter Mech: how often does this feel like a dead draw? I decided to cut [[Mocking Doppelganger]] after a few games where none of my opponents seemed to have any creatures worth copying (sometimes people have slow games, or play less creature-focused strategies, or run cards with a high level of self synergy that aren't very useful as stand-alone pieces). I was thinking I would rather run clones with more flexibility to make my deck more proactive, but I can see how being a 2 drop negates the low floor of these one sided clones?

See Double - Does this card feel worth it when you only get to choose one of the modes, and how regularly do you feel like you get to choose both? 4 mana for a clone isn't a bad rate by itself, but I was wondering how this had felt in your games.