Thanks a lot!
This is what I am doing.
First I have the above lister (locked tree/locked middle folder / unlocked image view on the right)
In the right panel I select and cut files. Then use Everything Search to quickly find the suitable (existing) folder.
Double click the folder or right click 'Open Path', so as to paste the files into that folder and then return to the point where I was.
However, when doing that, the 'unlocked' panel (on the right) is changed.
The above setting regretfully does not change that behavior.
(Background of asking to be able to open Opus a 2nd time)
Maybe, what I want, simply isn't possible.
If that is indeed the case, I guess I'll have to should ask the developer whether there is a way for Everything to 'force' using Windows Explorer instead Opus (being defaulted).