Does this project have only invite bounties now? Are you planning to launch other types of bounties?
Based on this thread:
https://bitcointalk.org/index.php?topic=5197897.0, right now there are 2 bounties running.
Invite bounty and Twitter bounty. Before doing this, it would be better for you to ask it on their Discord to make it sure.
That guy opened more than 3 bounty threads, I am not sure he is part of the team or not.
The Twitter campaign had a limit of 50 people, most likely already no seats.