My return proposal is just like any other proposal, it's not some hardcoded concept, I was just trying submit it ASAP (still, manually), so it has first id: 0. It has ridiculously big amount of daily pay, to be sure that it can consume everything that is not consumed earlier (i.e. by proposals voted higher than that).
And support for this proposal is also usual, that is, mechanism same as for any other proposal: people are voting for it (or not).
Currently it might be better to vote for one of the HBD stabilizer proposal to play such "threshold" role, because not only it will return those funds back to DHF, but in the meantime it will help with the HBD.
RE: Support Decentralized Hive Fund: Return Proposal