I have the original On One Summer Season with nowt but a laqueur coating, it maybe has one season of proper hard use with rust spots all over the lower bits from chain slap etc, but it will still be a bike frame long after I’m dead, I expect. TBH, it’s quite a few years old and generally not over used, but doesn’t look any different unless you really get down on hands and knees and scrutinise it.
It’s really not a big deal. if it is a big deal, asthetically, you shouldn’t have bought a cheap On One steal frame, they all do it.