Hi @AndyMc82
Welcome to the Sonos Community!
There is no way to change the default behaviour to Add to Queue in the Sonos app. I have added a feature request tag to this topic - it’s not a bad idea! - so it will be seen by the relevant teams for consideration.
Presumably you’d want a single setting that affects all controllers - otherwise, it would need to be turned on in each copy of the Sonos app that connects to the system and therefore be unlikely to actually solve your problem.
It should be noted, however, that we occasionally let a good idea slide if it’s determined that it will cause more trouble that it’s worth - if a feature is likely to cause more user error, confusion, or technical support requests than it solves, it may never see the light of day. I can see how this might be construed as one of those.
Having said all that, it seems to me that most times that a room full of people are given control over music, things go weird pretty quickly - my personal advice would be to change your WiFi password (admittedly, this is a bit of work) and take control!