Eliminate the concern by going with a valv-u-lator instead of a normal valve / regulator. I love mine.
Here's an example. Mine isn't the zeagle, but it's the first one that google found. The zeagle looks to be slightly larger than mine, which is a disadvantage, obvi. Also, I'd prefer to get one that didn't come with a second stage. My valvulator has a scubapro s600 on it.
In addition to eliminating the concern about din or yoke fittings getting funky, you also don't have to worry about accidentally splashing with the valve closed because it doesn't close. The black part in the photo is the fill port with a cover on it (similar to DIN cover, but smaller). Although you could easily create a fill adapter to use a normal fill station, I much prefer filling my pony off another tank. This way I've got zero concern about a destination balking about filling my pony after the airline made me remove the valve.
Actually that zeagle has some kind of knob on it. Not sure what that's for. Maybe the zeagle valvulator DOES have an on/off. That would be disappointing.
Furthermore, it's much smaller than a valve+handwheel+first stage.
Drawbacks? Price. I got mine used on scubaboard. I think I paid around $100 for two of them.
Zeagle wants a whopping $350 for theirs. Must be made of gold and diamonds.
Zeagle Envoy/RaZor II Regulator