Spell memorization Options

[Shadan]

I am new in IA. Played BG2 some years ago, now I want to try IA. I read that new version will come out soon, so I have a suggestion.
In PnP version you can memorize a lower level spell into a higher spell slot. At least it is in 3.0 and 3.5, I am not sure about 2nd ed. since I am plying 3rd ed. since years. So you can memorize for example one lvl 1, 2 or 3 spell into one lvl 4 spell slot. This would help when you need important buffs for example Chatoic Command, but you want to use some ohter lvl 4 spells also...
Just an idea for IA 4.3.

[Shadan]

I don't think that Chromatic Orb needs an attack roll, does it?

Nope, although a saving throw to negate the damage and the effect is given (hence it can fail, especially against tougher enemies)

In PnP version, CO was a spell from Wizard Handbook, and it needs an attack roll, however you get +3 THACO with it. I was not sure if this was implemented in BG or not. Seems not. But that ST makes it useless spell against hard enemies. I used to use against weaker-medium ones who are near to my mages or who moves toward they.