Currently unlimited on tcgone is base-power keepers. I know there has been talk about custom formats but until/if we get that you would already basically be able to do that with the “override rules” option if there was a format that just had all of the cards in tcgone legal.
Of all people here, I can bet you I’m the most excited for this, but I want them to first focus on fixing 90%+ of the bugs here first.
After that, THEN I hope they can add more sets to the unlimited format. At the very least, the format becomes a sandbox mode for all when all sets are added.
But for now, let’s be patient. 