I found a work around using AutoHotKey. As it turns out all the new tab "+" button is doing is sending Ctrl + N to File Explorer, which opens a new window in the same folder like I had been describing. Using AutoHotKey I was able to make it so whenever Ctrl + N is sent it instead runs File Explorer again (as if you middle clicked the icon in the taskbar or ran it again through start) which doesn't open the new window in the same folder, but instead to This PC (or Quick Access if you have it set to that) like I wanted. With Groupy set to automatically group explorer.exe windows it still behaves like opening a new tab. I also made it so this change is only applied when File Explorer is active to prevent issues in other programs.

Link to script: https://pastebin.com/taAZabCa

I still feel like this should be an option inside Groupy itself however.

This is also a feature on my request list as well.  It sure would be a nice QoL change to at least have this as an option in a future update.

Yes, please I would like to have this normal and natural behavior. A new tab should open a "NEW" tab and not duplicates it.

In Chrome [New tab] > opens a brand new tab

In Edge [New tab] > opens a brand new tab

In Firefox, in Opera, In Clover, ... basically anywhere all open a new tab. I am not sure why Groupy does a different behavior. You could add a duplicate tab option to context menu if necessary.

Actually, I never used Ctrl+N, I always use Win+E, but that's not a problem, Ctrl+N can stay, we are just asking for an option to change what happens when clicking on the plus icon.