Please Add no bonus option for PF

[Singularity]

Is an option to automatically block someone with bonus viable - probably, but will add to the already toxic community feeling.

I would actually expect this to reduce the toxic community feeling. Consider how it is now: Farm group is made, bonus player sneaks in, eventually the instance starts and the bonus message comes up. The party often at this point starts a witch hunt for the bonus, creating an air of suspicion. If the player is found out, he/she is kicked and possibly blacklisted, earning the ire of up to seven other people (plus however many others they may tell), while the bonus player feels hurt and possibly humiliated. If the player is not found out, the group may simply disband and start over, generating resentment among everyone present.
On the other hand, with a filter, the bonus player never joins at all, the others never meet him/her. No witch hunt and no blacklisting.