According to the FATF recommendations of June 21, 2019, which are mandatory for more than 200 participating countries, a KYC check can only be carried out for the purpose of preventing money laundering or combating the financing of terrorism and only if the transaction amount exceeds one thousand euros. There are no other regulations regarding the conduct of KYC.
Bounty hunters cannot be suspected of laundering dirty money or financing terrorists, since they do not invest their money when participating in bounty projects. Consequently, it is completely illegal for bounty hunters to require bounty hunters to complete KYC.