The new question is: how to tell Mp3tag, when adding [not sending] files to it [with the CTRL being pushed] via the shortcut available under the right click context menu, to put it in front of other software?
I add files to Mp3tag and I want to see them right away, without having to manually switch to Mp3tag
But while dealing with some other issues I realized that I had a possible solution to this problem. It seems that all I have to do is to use the FreeCommander as a filehandler and set in it a hotkey for a shortcut in Tools > Favorite tools > Favorite tools edit [which is an equivalent to shortcuts from File > Options > Tools in Mp3tag]
And if that hotkey is for example "CTRL + 1", then the "CTRL is pushed" and the files are not send to Mp3tag but are added to it; and the window of Mp3tag is put in front. And that is even quicker than having to evoke the shell menu and search in it for the MP3tag shortcut
Unfortunately with such settings it always loads up content of the whole folder. So if I would want to for a moment revert to selecting files and send only them tho Mp3tag, this would simply not work [because all of the files would be sent]. So I would have to have to version of shortcuts, one for sending all and second for sending only selected ones