Most projects allocate rewards as project tokens because they don't really have enough capital to pay the bounty participants their rewards.
This is why I gave a solution to pay potential cryptocurrencies such as bitcoin and ether from the the funds they raise.
If any project is denying this, then it means they want to scam the bounty participants.
This can be one of the ways to identify scam projects because the genuine projects should not have a problem if they are raising enough funds.
So it will be necessary for the project to think about how they can have money to start the project, and don't depend on the money from the investor. Yes, that can solve the problem for the bounty hunters because they don't need to feel worried if the project doesn't pay them. If the capital to pay the bounty hunters can be handled with a recommended escrow, then that will give another benefit for the project.
The investor will look at the project as a good project because they can prepare some money for the bounty money, they can use an escrow to handle the payment, so they can focus with the project until it's finished.