This is the real world folks Dash is not anywhere near replacing fiat. Most expenses will be paid down the line in fiat. This is the reality

Meanwhile we commit to a contract in which we pay 100 Dash per month, and dash falls in value. Contractor can't complete the job, ruined reputation etc. How does that help them or us?

On flip side we commit to a contract in which we pay 100 Dash per month, dash rises to huge new heights and the contractor is laughing, easy money for very little effort. That is all value being taken away from Dash for very little gain. Meanwhile other viable proposals fail to get funding because there is not enough slices left in the pie. Nic efor the contractor who gets the easy money, not nice for those missing out. Not nice for Dash getting bang for buck.

Long term contracts paid out in Dash is not going to work. I don't think hedging with derivatives will head anywhere good either. Keep it simple. Pay in Dash, renegotiate often based on exchange rates.