Is it really?That’s incredibly unbalanced with other feats and with CR ratings and with any character who doesn’t take these feats. Basically, that’s extremely unbalanced and would require a total rewrite of the game. It’s not a serious idea for 1e.
Not taking any feat for 12 levels so you can have 5th level class features at 7 level later than anyone?
5 levels or sorcerer/warlock/bard sounds very good on 12th level paladin, but you do miss all the good feats that would make you better in combat.