So without "pistons move t es" enabled, if you put down a redstone clock, a piston, and then another redstone clock, the piston will ignore the redstone signal and not try to push.

With this enabled, the piston will operate as you would normally expect, where it will push/pull the second clock when the first one ticks, but after a short while it will crash.

Here's a crash log with just the two mods (and JEI): https://gist.github.com/monodemono/3480543a0a2daa50e10555537b860279

I realize this is likely not an easy fix, but I felt it should be reported for posterity if nothing else.

@PrinceOfAmber Is this on your end?