This is an area of ongoing work.
I'm not sure which version of TilEm you're referring to. Pre-0.973, TilEm used a very simple method that was strictly limited to 4-level, interrupt-driven display routines, which looks nice for the rare cases where it works at all. Version 0.973 and later used a simple IIR filter, which flickers a bit but does work (to a limited extent) for a much wider range of programs.
For TilEm II, I'm working on a completely new algorithm that should work (without flickering) for any frame rate and duty cycle. It's a little buggy still, and does require somewhat more memory and CPU time.
I don't know what Wabbitemu provides in the way of tunable settings, but this new algorithm should not require any tuning by the user.
