It gets worse once you get touch spells that allow you to do multiple touch attacks. There is AFAIK no RAW definition of what to do then, other than implicitly. The Sage or FAQ stated that you could do all your touch attacks in one round, but that can get ugly.
Take, for example, the spell Touch of the Graveborn. It allows one touch attack per three caster levels. I don't remember whether there's a maximum. Now if you do some crazy CL boost shenanigans, this could mean you get seven or eight or more touch attacks with one spell, and theoretically you could deliver them all in the same round. Funny enough, for beneficial spells you are limited to touching, IIRC, seven allies.
Now as I DM I would house-rule that, too. I just haven't managed to think of a satisfying mechanism. Smiting spell goes all awry with so many targets, and Spring Attacking while touching multiple enemies does seem a bit over the top.
What is still unclear to me is the optimum sequence for a house-rule: Moving-casting-touching-moving, or casting-moving-touching-moving? The first fits the spirit of spring attack the closest, while the second is much more powerful.