Though the sealing elements of the various brands of “dry scroll” pumps may be dry and not actively lubricated, the bearings that the scroll faces pivot upon are packed with grease and excessive solvent coming across will cause them to fail sooner rather than later.
IMO, if your users are having complaints about diluting their vac pump oil with solvent they need to implement a better cold trap, if they are sending that much solvent across their vacuum system instead of complaints about diluted vac pump oil and varying vac levels on a wet pump, they will be complaining about failed bearings and damaged scrolls and seals on a dry scroll pump.
FWIW, ran a secondhand AI CleanVac unit to the point of failure before we got a cold trap that was capable of handling our system capacity.