I can’t remember all the details, but depending on the CPU you are running you may need some extra configuration on opnsense.
There were a few issues, on my servers, running on older Intel Xeon CPUs, but I eventually fixed them adding proper flags to deal with different bugs.
Other than that, running on a VM is really handy.
Nerfing things on a PVE game that’s supposed to be fun shows a lack of creativity.
You can buff the other things while finding better ways to increase the difficulty, instead of just boosting health and throwing more enemies, but that’s the “easy” button.