It seems simply not putting an oleophobic coating on the sapphire would solve the problem, no? Am I missing something?
It's not really a problem though. Any mark on the coating will gradually disappear. For most people at least it shouldn't be a problem. The OCD however will probably be getting new replacements every week at this rate until they realize it's inevitable it will happen.
Watching the forums since launch and it's pretty ridiculous how many returns for replacements have happened over little things like this only delaying orders of people who haven't even seen their order yet.