are proxy cards legal mtg Commander like Mishra's Workshop accepted? What Is WotC's Stance on

But seriously, I do get why they didnt want to ban Sol Ring out of the format

It's a one mana red burn spell, designed to be weaker than Lighting Bolt, and is strictly worse than a whole bunch of comparable cards

For Best of One, definitely no but that's because WotC seems to have no intention of making Bo1 a thing on paper, so even though you could technically play it on tabletop, for better or worse, I doubt we ever will

Accessories10 double-sided tokens, life tracker, deck box, and 1 foil-etched Display Commander

Tapping it lets you cast as many creaures using forage as you want

Pair that up with the card Dark Ritual, which adds three black mana to your mana pool for just one mana, and you can drop the Specter on your first turn