Office 365: Disable retention and version control by file type

Our users tend to put pst files on their OneDrive. This alone is not a big problem, but we have a policy of retention and version control.
Which means that every time Outlook touches the pst file and adds a timestamp, a new copy is made. This, in the case of a 1GB pst file, can fill your disk very quickly.
The solution is, of course, to eliminate the pst from the unit, but this can not be done due to the retention policy.

So, my question is: can we exclude all the pst files from the retention policies in some way and / or reduce the number of saved versions for this type of file?