MY OPINION: it will be wise if this forum creates a board for feedback from bounty hunters regarding their experience with bounties especially with payments and defaulters should Be dealt with. possibly blocking their ANA Page or something else.
I guess bounty hunters should just stop talking, complaining, and asking for help from moderators and take advantage of the option available to them. The forum has already created a flag system where anyone can create a flag against someone who has violated a contract. See this thread I posted two weeks ago for example
https://bitcointalk.org/index.php?topic=5165178.msg51824246#msg51824246