Respect for all your work, that looks pretty well-thought-out. To approach the whole silver-bordered matter a little more carefully, I thought how about we start with a silver-border legality list rather than a ban list? Meaning silver-bordered cards remain banned unless they are on that list.
To start of small, I'd suggest cards that don't behave any differently than regular Magic cards - things like
Uktabi Kong and
Target Minotaur.
More importantly, though, most Contraptions also just contain regular Magic abilities, except for the couple that involve dice-rolling. Contraptions might actually be fun, or even the theme of an entire Commander deck. I found it a bit lazy from MaRo, who had pledged to find a use for Contraptions during his lifetime at Wizards ever since the creation of
Steamflogger Boss, that he just eventually relegated this task to an Un-set.
So I don't see why, of all things possible, Contraptions would have to be excluded from Commander by default?
Especially given that
Steamflogger Boss is actually legal in all Eternal formats.
With half-mana and half-damage etc., I can see the point - but still, if these cards behave normal otherwise, Donkey tribal should totally be a thing!
I mean, if you get one of your opponents to 20.5 Commander damage and then lose, that's simply your fault for putting too much half-damage stuff in your deck!
