Antonio Victor Garcia-Serrano reported issue with multi-camera shutter release sync when using MECHA with a trigger splitter like Dynamic Perception Mux4 box (, a Promote Control Hub ( or a couple of Pixel 2.4GHz Digital Wireless Remotes (
I cannot use the Pixel-Wireless remotes with Mecha, but when using either the DPMux4 or the Promote control to trigger from the "cam" output of Mecha I have noticed an unreliability on the syncing which happens quite often and does not happen at all when using a simple remote control.
when directly triggering the shutter signal with a simple remote I "always" get a "perfect" sync up to the second decimal.
Here is my proposed cause of the problem. Since the Mecha cam port is isolated, current needs to flow from splitter to cam port and then back to splitter. This may cause distortion of signal, more so with coiled cable. With focus opto turned on for long enough duration, the focus wire becomes a ground pin and may reduce the signal distortion of shutter pin.

Antonio Victor Garcia-Serrano reported back:
increasing Mecha focus time to 1sec has sorted it! (anything below 1sec, I have tried from 100ms to 900ms, does not always work). Cameras are SonyA7S.
I have repeated "sync" tests again with a 3decimal stopwatch + a tap of water dripping (even though it might not be as good as camerasynch tester, but still good enough for my purposes) and it is only with 1sec that I always get consistent "sync" results.
Hope this help for people using Mecha on 2 Sony cameras. Not sure same issue affects other cameras.