Those bounty managers, who don't respond to their participants are not worthy enough to be a bounty manager in my opinion.
Bounty managers are bound to respond to their participants because they are getting paid to manage bounty campaign on behalf of the XYZ company.
Bounty manager is not only meant to add participants, update spreadsheets and distribute tokes/coins, but to communicate, respond, solving issues on behalf of the company.
Enough said of bounty managers.
Now the bounty hunters also need to be very responsible.
Before contacting bounty managers with your question, you need to check if it is already answered or mentioned in op.
Moreover, read the terms very carefully to avoid misunderstandings.
They manage tons of participants, they are doing tons of works behind the scene, so bounty hunters should give them time to get an answer.
And also bounty hunters should do their tasks very carefully, so that they don't make any mistakes which ultimately lead to bounty manager's support.
So bounty managers support bounty hunters and vice versa. The best practice ever!