I just received emergency FDA approval to produce them! I love this forum. Always entertaining and quite informative. Stay tuned for full approval if you are interested.
Ive had them hit with a double roller chain and not hit with one. I don’t know why a couple hit and the rest didn’t.
Rather than spend a bunch of time running down why they hit I just don’t use them. In retrospect I probably should have figured out why but I’ve never had an issue without one.
Mine seemed to have a bit more clearance than what you have there. I don't think you would have any major dramas running it that close, but then there are also heaps of motors running around without an oil slinger if you aren't keen on using it.