I own 2 copies of the game (1 via Steam and 1 via the standalone Launcher).

I installed the Steam version and until now, used the "-provider Portal" Steam Launch option to switch between them. With Lunar new Year approaching I decided that, typing 2 words to change Versions, is too much of a hassle and looked for an easier solution.

Turns out, it's really simple: By adding the GW2.exe, from the Steam installation, as a "Non-Steam Game" you are able to create differnt Shortcuts, with differnt Launch options, for the same Game.