Upon finding out that Visual Studio (not Visual Studio Code) had stomped on the file association for .TOML, and spending a good couple of minutes trying to shut it down..

:-| this should be handled in a matter of seconds

Ah, yes. This feeling when you double click a .cs file with that naive mindset that you could quickly take a look at the code. Only to realize a few seconds later what horrible mistake you have done. Now you will need to wait minutes for Visual Studio to slowly get its fat ass up and load all universe to display to you that one line of code that you wanted to see.
You can’t wait any longer and are trying to cancel the shit and open that file in fucking notepad but it’s too late. You can’t stop the train at full speed. It will keep loading and loading just to close it afterwards because you have clicked on the close button a thousand times desperately trying to kill it. Now you can finally open that .cs file in a text editor.

IDEs should only associate with their own project definition files by default.

I hate when image file formats get associated with Photoshop or other image editing programs. Default windows image viewer isn't external program so you can't easily associate it with image files. You need to dig into registry to take it back.