Seems a reasonable enough tournament improvement.
Just a thought, would it be possible to simply prevent a player entering a tourney if their cards were, say, maybe 30% over?
Like if you have mostly silver level cards you can only play up to silver, until you get, in this example, 30& of your cards leveled to gold. Once they are, you can't play silver any more.
Adds to the motivation to level up your cards too.
Not really. GF cards alone break that entire idea... plus there's the question of why you'd want to penalize partially leveling up your deck even if it can't be used in the tournament. I think it would actually motivate people to not level up cards. "I can go this far, but if I level up any more of my cards I have to go into gold and I don't have enough to level up all my cards."
You certainly know more about these things so happy to take your advice.