Deleting virtual server should also remove all the relevant files on the system as otherwise they are just needlessly taking space on the drive. For example, if you delete a virtual server then it's access and error log files remain intact in /var/log/virtualmin directory. On one of our Virtualmin servers that was strugling because of storage space insufficiency, I was surprised to find lots of access and error log files for the virtual systems that were gone long time before. Luckily I was able to easily identify them, because they all belonged to digital users like 503, 661, etc. instead of actual usernames (because their respective users were deleted) and remove them from the disk. It would be really nice if Virtualmin cleaned up ALL the files and settings related to the virtual server that is deleted from the system.
Deleting virtual server should also remove all the relevant files on the system