Yep, do to most spells what the Rebalancing Project was doing to Polymorph, break any open ended spells and effects into quantized chunks of effects, you can summon/call/create a creature, but not from a monster manual, you get to build your own epic beastie out of generic outsider HD. Unless you are calling up an existing critter and bargaining/dominating it, which is a different spell use entirely(Scry+Teleport/PlaneShift+Mind Control).
I figure direct damage, and the various status effect things are easiest.
Oh, and make it easier to expand the spell's area of effect, or range. After a certain point, it's tactically insignificant(whats the difference between a 120ft radius spell and a 1200ft radius spell in tactical combat unless you are screwing with Explosive Spell or fighting an army of mooks?), but flavorwise very much so.
Something has to be done about mitigating factors though. The ones with expending more resources for a greater effect(xp burn, expensive material component/focus, more spell slots) are asking for trouble, if left open ended. Casting time increase is another one, the 'cost' diminishes once you get it out of tactical combat(anything more than a round, essentially), especially if increasing duration is cheaper than the benefit of increasing cast time.
Some of these will have to be relegated to
ritual only stuff. Plot Casting shouldn't come out of the same pool as combat casting.