Pass the default mouse button

In my "All Apps" group, I have Button 5 set to Command Key Down and Button 5 (mouse-up) set to Command Key Up. This allows me to use that mouse button as my keyboard Command key so I can more easily use copy, paste, and other functions in nearly every app without having to do a finger-twisting tango.

However, in one specific app (let's call it AppX), I want Button 5 to just be Button 5. I have set up a group just for that app and I can set all sorts of things which apply only to that app. However, all the settings in the "All Apps" group are applied to AppX unless I specifically assign a different function to a particular button within the "AppX" group. I can't seem to find any way to assign Button 5 to Button 5. I can assign all sorts of other things to Button 5 in the "AppX" group and they will take precedence over the Button 5 assignment in the "All Apps" group when AppX is the focus. However, just getting Button 5 to be passed as Button 5 is either not possible or I can't find the way to do it.

Is it possible? If so, please share that with me!

If it is not possible, how can I request a feature from the developer?

Thank you in advance for any useful response you can provide!

edit: I know now that I used the word "group" wrong in this context because it refers to a specific function in BTT. I hope it's still clear what I meant.