Is 20 in your main stat compulsory?
I'm currently on the start of my 4th playthrough (400 hours as of writing), playing a level 2 melee leaning Ranger with the intention of running Swarmkeeper (it's my comfort class). My stat spread currently is:
10 STR
17 DEX
14 CON
15 WIS
10 INT
8 CHA
At level 4, I'll take ASI to get DEX to 18 and WIS to 16, and at level 8 I'll take savage attacker. I've done this build before (https://www.reddit.com/r/BG3Builds/s/3PWSNb8aJH), and I'm running it again cuz I just love it so much, but the problem this time is that I'm playing with a friend (she went with hexblade warlock) who's new to BG3 so I wanna let her have Ethel's hair. This means that even with Shar's mirror, I can't reach 20 DEX unless I take another ASI at level 12.
However, when I play this build I usually take a 1 level dip into Wild Magic Sorc for booming blade, and it makes me hit like a truck. I can also do fun things like hitting a melee opponent with booming blade, teleporting away, and watching the opponent run themselves down. So my question is, do I wanna take booming blade or ASI to get my dex to 20?