I've noticed some strange behaviour when adjusting the pattern length on NL for Android. It's fine if I change it to 8 or 4 steps, but with other numbers it can't seem to join the loops properly. For example, if I have 10 steps in patterns 1-4 and try to loop them, it plays some of the patterns twice and some of them once, seemingly randomly.
This basically means no odd time signatures are possible, as far as I can tell. Any chance you could look into this if you're reading this, Oliver? I can see how it might get tricky if another instrument has a conflicting length. One possibility I can think of is to have a "base number of steps" option for new projects, and to keep it fixed throughout a project.