Alright after 2 weeks of playing without issues I think I've found the source and workaround for at least my problems.
Previously I have also updated my gfx-card drivers to the latest but that did not fix the issue though it could factor in.

+1, started recently for me ( a week ago )
The issue occurs only after opening the map. Sometimes it drops to 2-3 FPS straight away.
Sometimes the drops happens incrementally by 5-15 FPS at a time as you open the map.
Happens on both Vanilla and Modded servers.

Can confirm that adding the magazines directly using setPylonLoadout works perfectly fine but in the Master Arm module things gets iffy.

On the top of my head you may lose things like mission progress saved in profileNamespace. Does the Virtual Arsenal save data in profileNamespace? From a quick look I don't think so.

The extent of the damage would depend on what kind of missions the player is playing.

Confirmed, same issue here.

The head model actually turns but the camera does not.

Thanks oz but I think you missed the point of my report, it's only an error message, no actual error. The Arsenal works superb in other aspects but it prints the error message when used as designated by the documentation.

This only happens with allowFunctionsLog = 1; in description.ext so this is a minor issue on par with unnecessary log entries.

Confirmed, modelToWorld now returns z = 0.892423.

Ticket can be closed, huzzah!

Added more info on my workaround.

Haven't run a dedicated test but the mission that made me post the issue is now running as expected. Directionality seems to be working both in editor and in MP. Will run a test to confirm this and report back.

Edit for clarification in description.

Upvoted!

I do like the idea of a serverConfig command which can retrieve cfg parameters like hostname, motd and maxPlayers in an array.

Confirmed, I can reproduce it just by placing a marshall in the water just off the coast with a single move waypoint onto land. The marshall spins around wildly in the water and takes ages to get out.

The getting out part I noticed was really slow when driving it myself so that probably is just the vehicle that need a slight buff on power.