Level Syncing isn't the best solution

[Maeka]

Nope, just nerf abilities above the level of the dungeon. That easy. You can choose to do the whole rotation, but you'd be better served by doing the rotation at level. You can either nerf them so much that abilities above the cap do literally zero damage or miss, or, you can nerf them so that they don't do enough damage to be more potent than a lower level rotation.

I'm of the opinion to just let higher level players be a tiny bit more powerful, but if you want to nerf the abilities to the seven hells in order to maintain balance, feel free. Same low level rotations available to both, nerfed high level abilities reserved only to those who've already unlocked them. The rotation itself doesn't have to be better, just there, in order to fulfill the wants and needs of the OP and those in favor of a more robust level sync system.

What, may I ask, is the point in doing that!?

"Here, have Fire IV in Sastasha..... but it will do jack all for damage, so you might as well not even use it."

And how would you TELL which abilities are good and which aren't? "Gee, is Fire III available in Brayflox normally? I gotta look it up to see if it is even worth casting" ...

Really don't see what you'd gain out of making the higher level abilities almost worthless, might as well just simply level Sync. They both do the same exact freaking thing. Well, ok, I suppose you could waste GCDs on worthless abilities.... but why?