Blue
Ravenous Bugblatter Beast of Traal
Right now once the primary ability score gets to 20, I'll see the occasional half-feat for something unusual. But with this, there's the same high push for the first tier feats and an increased push for +1 to primary/secondary ability score half feats, but that would leave other feats much further behind in the selection weighing, effectively shrinking the available feat pool.
Another issue is SAD vs. MAD classes. A rogue archer can get way with just a good DEX, but a melee paladin needs STR (or DEX), CON and CHA.
One possible solution that addresses both of these is if a feat is increasing an ability score that starts at 13 or lower, it gets +2 instead. Since that's a definite bonus to saves and skills, that's valuable always. And at 13 or lower it's not your primary ability score, and either isn't a secondary or you are already spread thin and it gets a bonus to one boost.
Another issue is SAD vs. MAD classes. A rogue archer can get way with just a good DEX, but a melee paladin needs STR (or DEX), CON and CHA.
One possible solution that addresses both of these is if a feat is increasing an ability score that starts at 13 or lower, it gets +2 instead. Since that's a definite bonus to saves and skills, that's valuable always. And at 13 or lower it's not your primary ability score, and either isn't a secondary or you are already spread thin and it gets a bonus to one boost.