I finally decided on PCSS for the party, and they're now up to level 22. G. P., I took your advice to go slo-o-o-wly, and it's working. Sort of.
As you know, you have to reach Archmage status before you can really hammer out those higher spells. (A lowly sorcerer trying to cast Shrapmetal at level 4 is just pathetic.) My Sorcerers are both Wizards now, but just aren't hacking it in the Archmage promotion quest. I know I've done Corlagon's Estate numerous times in the past, and I never used Telekinesis, AFAIK. But that one switch has me stumped. It's the one that's in a short passage off a main corridor, behind a waist-high wall. The wall is unjumpable, invulnerable, and a blasted pain in the neck! There are no Levitation spells in MM6, so that's out. (The switch in question opens a secret door to the Lich who holds the Crystal needed to advance to Archmage.) Does anyone know of a way around this? Or do I just bite the bullet and buy a very expensive Telekinesis spell? Thank you all.