I've gotten it to flash and lag a bunch and crash on my main world, teleport significant distances in the direction I'm moving, and disabling player movement once exiting the zipline
Fairly easy to reproduce the flickering, teleporting, and movement lockup, but I've only gotten it to crash twice
Steps to reproduce
-With both mods enabled, place a line of medium electric poles, make sure they're powered
-One tile above, place a line of belts
-Equip belt immunity equipment, zipline controller, and zipline trolley (Tested with programmable controller and fast trolley)
-Get on the zipline and move with the direction of the belts
Videos:
https://www.youtube.com/watch?v=-D07N_N0k4c (in my main world)
https://youtu.be/pYG1jm2R_qQ (reproduced in editor)