Sorry for the late reply... I am using windows 10 myself. The file locations shouldnt be a problem. When visual studio loads, and you go to grab Project templates, it looks in your documents(or in some cases the OneDrive), whatever your pc deems the active "Documents" folder. Then looks for Visual Studio, the templates folder etc.
I had my vb template installer look for the same thing(in the same way, where it found OneDrive/Documents intstead when the thing is used) and places the templates in there. If you get the C# templates, and have ran the template installer for vb, it will be in the same location.
From there, you dont directly see on the giant list of all templates the VB mono stuff, youll see on the drop down list a new menu item called MonoGame and clicking that will show you the proper templates.
PS: my thing is designed to detect the location similar to how vs detects the places as well so they always target same place.