I'm trying to work with high volume logs using `Merged Logs` (as I need to combine logs from different sources into one) that reaches 10 000 entries per minute. LogViewPlus is very often stuck in `Unresponsive` state or is very slow the respond to mouse actions.

I've got 7 GB of free RAM on a 12 GB system according to Task Manager.
The process LogViewPlus.exe is consuming ~3 GB of private working Memory and 50% CPU load on Xeon Platinum 8160

Yes, tailing is one of the main benefits of using LogViewPlus.

Ok, I'll count the next time. But the avarge of three hours of logs is 46 log files with a combined size of about 1,5 GB, at the moment. I've still haven't added the logfiles of the three other SharePoint servers.
But I really can't reload the logfile (is that refreshing) once LogViewPlus is frozen...

Yes - reloading is the same as refreshing.

I suspect LogViewPlus is frozen because it is resource starved.  What I would like to do is find out why / if this resource starvation is happening.  Hopefully, you can see the performance degrading over time and narrow down where the problem might be.