So far, the GOG galaxy 2.0 builds have been really great and have been increasingly addressing many issues and adding features.
There's this one feature, which BTW was present in the older versions of galaxy, wherein you can run different executables present in particular games; like say if I wanted to run a game in dx10 mode using its dx10 executable, I would simply choose an option 'Other' which was located just next to the play button. I could find a list of additional game executables as well as configuration and setup executables (if any) for that particular game.

Galaxy 2.0 seems to be missing this feature. Tried as i might, just couldn't find any option for it in the game menu. Wonder if they have yet to add it.

So how are the standalone expansions that used to be hidden behind the More/Other sub-menu like Silent Storm: Sentinels now launched if that old route is not implemented?

Not that I ever liked that solution anyway, as the best option would be to allow us to add multiple custom buttons under the main launch button, so that any alternate source ports, setup wizards and even the other games in the same series could be easily seen and launched from the same panel/page/view or whatever the largest frame in UI is called.