This isn't necessarily a game-deciding advantage, but I think it's still an issue and it only gets worse if there are no worthwhile $2-cost cards in the Kingdom
Except the Tithe is a 2^ costing card and if a player purchases Tithe (getting another green card unfortunately) which can trash an estate from in hand for two spoils and try to spike after the shuffle with 2 temporary golds and maybe an unused coffers.
and uh the turn 1 chalice effective split of 1/6, which is Not Ideal
If a player gets the 1/6 spilt is it too different from getting the usual 2/5 split? an early 6 getting a Gold is not too importantly different from a terminal +$3 action card until mid game when being an action becomes a bit of a liability. And as far as giving out the 2/5 split more often, that is not to different than baker's free coffers during set up. If this effect creates too many uneven starts, I feel that players can agree to start with sorted decks if randomness is too impactful for them which many tables do, already.
Most games with Chalice will not have any Potion-cost cards other than Ritual Tithe in the Kingdom
If that bothers players too much they can build a kingdom that includes potion costs like alchemy recommends or with any dominion kingdom that includes "custom cards" they can ignore it and pick a new kingdom card that match's what they are looking for (But we can't do that! What if I run out of different interesting combinations for the small amount of official cards and even smaller amount custom cards that are out there. I desperately need every card, and every line of text on every card to be relevant to all randomly built kingdoms /s)