This shouldn't be different than putting private keys in decentralized exchange, if I am not wrong. So either use throwaway address or don't use platform at all.
Just keep this in mind, accusing bountyhunters.io of scam is accusing many projects and startups of being scam, as some of them share the same developers, team members, advisors...
@bountyhunters do you escrow bounty rewards?
I prefer using a throwaway wallet or a new one until some guy will post that they are indeed stealing people's coins, it is not ok to give your private key, but there is a way to do it while withdrawing your coins, then let's check these options and wait for the updates from other bounty hunters.