Is it likely that RUF reports can be used to generate negative reputation for my server?

No, mail server operators will generally not punish you for sending them failure reports they explicitly opted in to receive - provided your volume and format matches reasonable expectations.

Any software designed with the "obvious considerations" listed in RFC 7489 Section 7.3 in mind should limit the output to a fair level of traffic amplification. You are only forwarding about as much crap as was forwarded to you, which is not a particularly large increase for internet standards.

Whoever does not want failure reports (any more) can revoke his opt-in.

Note that sending or receiving failure reports is not exactly common these days - I suspect many share my opinion that it is simply not very useful beyond aggregate reports, and produces mostly unnecessary privacy concerns.