I agree that some of the restrictions are too much and the power curve on the upgrades has gone too much in the other direction.
I understand the need to not allow OP players be Evo'd to become more OP, but it can be difficult to even get lower players to an even playing field as others, as is the purpose of Evos. If a player is quick as a base card, that instantly disqualifies them for 95% of Evos (for example, I like to Evo Irish players, but haven't been able to use Ogbene due to his base 89 pace).
I think another over-restrictive measure is the exclusion of positions in Evo eligibility. I've yet to be able to Evo Troy Parrott as, despite being a ST, he also has a CAM secondary position that disqualifies him from most ST Evos. I posted about my wish for a way to remove these secondary positions for the sake of Evo eligibility last night:
https://forums.ea.com/discussions/fc-27-feedback-en/removing-secondary-positions-for-evos/13777594