"I'm curious...anybody out there been riding a conversion for over 5 years?"

Yes. In the seventies and eighties (and prolly before), a common form of winter training was to remove to freewheel, derailleurs and shifters from your bike and slap on a 3/32 track cog plus bb lockring. Shorten the chain. When the weather improved, toss the chain and re-install the mechs. You would never remove the brakes from such a setup. This way you could work on cadence, and not worry about winter grime caking your mechs.

A couple of manufacturers even sold derailleur bikes with flip flop hubs as part of the standard setup for a bike, so you could use a track lockring in the winter if this made you feel safer. Usually found on entry level bikes; I won't tell you which ones though; I don't want you guys snapping up my sources of cheap vintage flip flop hubs .