btw, I was thinking about this and had to ask, why 70???

At ph_fps_maxlock=70, the stepsize is 0.0142857142857... s.
It's trancendential and I don't know about using trancendentials as a stepsize, is there advantages?
Even if you round it, it still bring images of zenos paradox to mind and a trancendential stepsize that never "steps".

I would argue that another choice might tidy up your ODE system a bit?
In the range of 70, 64 gives a better alternative with a stepsize of 0.015625 s.
I prefer 80 though with a tidy stepsize of .0125 s.

Just curious.