Just a heads up that we're still investigating.
"Perhaps it is my subjective bias, but I can't remember these issues prior the "Thermal sights update", which was released a few months back"
This is just a simple rendering trick, it may consume a little more GPU/CPU time, but it's a single threaded feature and can't result in all CPU threads being maxed out.
I'm sorry, I have yet another request...
Please have the host do an 'In Progress Save' when the problem appears, and upload/link it here. I'm hoping it might capture the issue.
The most recent ROTER-HERBST sce still has problems on the Zivil side, some units still have invalid Ids. One possible indicator is that the unit icons won't show a name(though I'm not 100% certain).