Baldur's Gate : The Sword Coast Chronicles : NWN2 Persistent World

While I'm on the fence about even whether or not a sorc even needs much improvement, but I did think of something that while not massive might help a sorc build.

At the 15th level the sorc can get a free sla
22 gets a second and 29 a third.

The sla can be chosen from your entire spell list, but level determines the cool down of the sla. Now I would think qc and those better at considering could give feedback, but something like

1=1 min
2=2
3=3
4=5
5=7
6=9
7=12
8=15
9=18

I think this doesn't compete too much with the lock but does give it some ability that may boost it in a small way. Especially when rest is limited.

I think in the past it was discussed to give Sorc all social skills as class skills like in PnP. I liked that sugestion. Dont see need to improve their spellcasting. If you want SLA you can pick Archmage as some do. Spontaneous Spellcasting allows for excellent use with metamagics. Spells you dont need still can be cast without error from scrolls like teleportation,dimension door...
CHA based spellcasting allows good combinations with Pal/BG/Warlock...boosting saves and DivineShield.

Overall a strong blaster/dc class. May have problems with low skill points...