I'm pretty sure their strategy is "get something back" when someone leaves. They're definitely not doing anything to make this a great place to be long term, as
@Acrofox outlined above. They've had crazy turnover numbers (10 in the last 8 years) and I'm sure they're tired of buying types, but the dept. manager's strategy of "trap with the agreement, and act injured/get pissed when someone complains/disagrees/requests improvements" doesn't really incline people to stay there.
Technically, I could quit and be clear of all obligations after March 25th, as long as they don't schedule recurrency prior to that date. The problem would be having a new job waiting on that narrow window of opportunity.
For now, the plan is to find somewhere else to fly and attempt negotiating the exit payoff. Prorating the balance is the opening stance, seeing as how that's industry standard. If they won't negotiate, I guess I'll be making payments for a while. They're realizing that their reputation in the area is falling rapidly, (not through any direct action of mine, but the situation did get publicized when I had to back out of the new job) and I believe that's made them panicky about being able to find a replacement. I've had several comments directed my way about "how it's a good thing you stayed, I can't get anyone to even to talk to me about flying here full time."