I think it might be easier to pause the printer before capping, remove the build head, completely clean the part on the build head, replace it, and resume. Just letting the part 'drip dry' will never fully remove the uncured resin.
If you can stand a thin layer of uncured resin, I would then find the thinnest resin you can that doesn't react with the PDMS window. If you don't mind scrapping a tray, FunToDo makes a very thin resin. Just know that you will scrap the PDMS after one build.