I don't see after run oil hurting anything so I have always said if it makes you feel better using it then by all means use it. I was sent a big box of old two stroke engines from a friend that just ran them for a while then tossed them onto a bench, never ran them dry. His thinking was that the fuel evaporates and the castor oil stays until it hardens. When I need one of these engines I just heat them up until they roll over then take them apart and clean them to get rid of the old hardened castor. So far I haven't found any rusted bearings or cranks so there must be something to his thinking. I do use after run oil when I'm reassembling them, that or the Marvel Mystery Oil.
These engines were from Nothern Calif. and there is himidity, rain and snow but nothing like the mid west or the coast of Texas. I think humid regions of the country makes storage harder and I'm not exactly sure how I would go about it if I ever moved to the mid west? I store engines for a very long time, it could be years before I need one.