I've confirmed this occurs on the latest 1.10.6 with a project having a substantial number of folders on disk. Our project has 20000+ files and 2000+ folders.
I setup a new project, imported VIU 1.10.6, latest SteamVR and Oculus. Play in editor was responsive. After generating 10000 txt files, there was a small lag, but not a big problem.
However, after generating 1000 folders running "For /L %i in (1,1,500) do mkdir folder_%i" a few times, a 4.5 second lag occurs a few moments after the scene becomes active. See the attached screenshot.
I've uploaded the test project here: https://drive.google.com/file/d/1SuFDpR-L6_6kbS11GbyYLbikZvaGJUMe/view?usp=sharing