When I think conversion, I usually think, complete top end, then there is only the slide to frame fit, that would be different as far as wear, and that would depend on what the original was meant for, and the conversion. If I have a mated slide and frame for best accuracy, then I probably would not want to disturb that relationship, but if I have a service piece, and check the frame to slide fit, and there is no abnormal rubbing why not. The .22 conversions, with the exception of the Colt Ace, are alloy aluminum slides and won't hurt the frame, and some have independent slides, like the Marvel, so again, don't hurt anything. Now internal conversion kits, like the .460 Rowland, used on a .45 slide, I would probably buy a slide to go with it and dedicate it to it.
I had a customer who had me install a Wilson barrel, in his enhanced series 80, a brand new pistol, I asked why he wanted me to do that, as the factory barrel will probably shoot well, and with a match barrel bushing and fitting the link, would probably shoot very well. His logic, was, shoot the Wilson, ( and it does shoot well ) and have the factory fitted barrel as a spare. Go figure. You go out of business arguing with customers, but I do want to know, why they want the work done, and their expectations afterward.
Some people may argue here, but caliber conversions on 1911's has one head ache, the ejector will normally need to be changed, I have 1 swap caliber 1911, from 9mm to .45, I don't install the retaining pin on the ejector, so I can remove it by hand or with pliers and push the other one in, when assembled it is captured and can't go anywhere, on disassembly it could fall out, but does not, and I'm aware of it, and things just go smoother.