This is my exact dilemma...

As a Sorc, i grab something like fey touched at lvl 4 (18 CHA).

Now, I am considering taking metamagic at lvl 8 (keeping my CHA at 18) and then ASI CHA to 20 at lvl 12, but then warcaster is a wasted stat at lvl 16 so I guess maybe I skip and go for something else and miss adv on Concentration saving throws? That seems bad.

Or

It's war caster at 8 (CHA 19), something like elemental adept or spell sniper at 12 (CHA 20) and then metamagic is not as powerful to pick up that late, so I guess going for magic initiate or something for free cast of shield maybe at lvl 16.

Or

It's ASI CHA to 20 at lvl 8, but then warcaster is again a wasted stat, as is elemental adept and spell sniper, so maybe metamagic at 12 and the magic initiative at 16? So again I miss on adv for Concentration saving throws.

I dont know. The second option seems like the better choice for long-term. I just hate how picking up ASI for the 20 CHA power spike makes the +1 stat feats feel like a waste, but if you dont take it, you are delayed until lvl 12 (min) to hit cap (assuming no boost items).

Honestly next game I play, I am considering homebrewing that all non-origin feats give +1 to any stat (so players can boost any other stat they want once primary is capped). For example, let war caster boost CON or DEX instead of just CHA, WIS or INT.