[LAD] High-res PPQn

Hello list, I recently wrote a sequencer for multi-touch/collaborative music composition as part of my thesis. I currently set the PPQ to 128 which ought be enough for demonstration purposes and early testing. Now, I am wondering how to support higher PPQN efficiently. Some of you guys might have an experience in doing that; I've seen that renoise supports up to 4096 PPQN and DigitalPerformer uses some kind of variable clocking. Have you heard or implemented of techniques that are smarter than just cranking up the _fixed_ clock resolution? As timestamps I currently use 64bit ints, I guess I could encode the timing as (tick, +subdivisions) and poll the timing for the next event(s) and set the clock accordingly. Would that be worth it? Any general opinions about the max PPQN? thanks, so long... Niklas