Having a player join using Steam Multiplayer desyncs all the non-host clients.
After some minor oversights on my part and a bug report forum post, I have now indeed been able to conclude that unfortunately this mod is the cause of this. Staff in this (https://forums.factorio.com/viewtopic.php?p=684436#p684436) thread seems to have some useful input on this.

The issue is that the client and host get desynced, probably because the host's movement speed is not shared correctly. This then causes a desync on host movement.

Mod was not designed with Multiplayer in mind and most likely will not ever be.
As we are bypassing exoskeletons toggle and mod works when the toggle is OFF, otherwise speeds are multiplied and you go light speed.
I have not found a better way.

What is accumulitave exoskeletons speed % of the person when he gets desync?

Update: ill look into "global" table was renamed to "storage" that was mentioned in the forum.

It would get desynced regardless of their speed or mine.
It might be worthwhile, if you don't want to support it, to see if it's possible to disable the functionality in multiplayer to prevent desyncs. I just thought I'd bring it up considering I could not find a note on multiplayer incompatibility anywhere.

Re-read, giving an update on What is accumulitave exoskeletons speed % of the person when he gets desync?, empty inventory, button off, no zoom change. Desync occurs when I, the host with a non-default zoom and exoskeletons off, moves.