Just a heads up for anyone curious, as of date on this post:

-Spirit airlines flight refund for CANX personal leave due to military orders-

Full refund of flights but required a signed letter from CO. They would not budge with merely a cancelled leave chit. There's an easy quick option in their online chat interface for this to upload a pdf though.

-Sun country flight refund for CANX personal leave due to military orders-

No refund but did not require any sort of documentation to convert full cost of flights into redeemable voucher for 1 year. Had to call their support line.