Good point - here's a few other situations I thought of that are sure to cause grief if an in-house requal costs 3 years:
1) MWS pilot gets tagged for non flying 179 or 365. The only way to insure yourself is to take an I/Q checkride right before you leave, so when you come back you aren't unqualified, just non current. That does take sq/cc approval for an out of zone check, and given what I've read in other threads about some sq/CCs, that may be easier said than done.
I don't think that would work for your Cessna problem though, because once you get the qual in the Cessna, it voids your previous MWS qual, no matter how current the form 8 (no dual qual for the average joe)
2) MWS female pilot gets pregnant - during her DNIF period, her checkride expires. So does she pick up 3 years just to requal once she pickles? (This can also expand to any pilot who has a long term DNIF)
3) MWS pilot gets a Q3 and is directed to fly X sorties/sims before refly - does this count as an in house requal?
Again, who is gonna track down every "RQ INST/QUAL" form 8 and attach an adsc, I have no idea. But it seems like the AF didn't think this one all the way through (shocking). It used to be clear that they were picking and choosing what they wanted to follow - now they just muddied up the waters.