Very clever implementation - seems to strike a balance between the ethos of Bitcoin (incentivized yet voluntary participation, limited middle-persons, onchain) and the need for Bitcoin-native projects to have known costs and miner’s to hedge against low feerate periods.
You may have seen the deal done by Block Green to seed a miner with capital in exchange for the total revenue of their next 50 blocks. This seems to suggest that some miners would also like upfront disposable capital. I wonder how this implementation might allow for something similar - perhaps some adjunct service that offers up the collateral for miners with some accompanying stipulations for handling defaults?