Ofcourse it is!
Nowadays, I notice most of bounties have strick rules, making bounties more organize and I like that Bounty Manager requesting Proof of Authentication to limit scammer .
It's been one of major mistakes of bounty hunter like me not to read rules and requirements of each bounties ending up not getting stakes so it's very important to read and understand each rules to ensure that we're doing the right thing and not wasting our time and effort.
Although it is important to follow the rules implemented by some manager, but some of this rules been very annoying for me, why? ive experienced it. Although i follow the rules, but i still never get the stakes, i dont know why but maybe the manager did not checked it properly, i hope everybody must be fair.