I open specific vsts like this:
Just open up Halion(or whatever vst) as an instrument track one time, and then save it as a track preset.
Then make a shortcut for a new instrument track (e.g. Shift+Alt+i) and then just open the track preset.
I know it’s not a faster option if you just want to open an empty Halion or something. But i save whole vst presets combined with inserts and EQs on the instrument track this way. So if i have Kontakt open with my own sound and a few plugins on the channel and send effects, i can save it as a track preset and just need two clicks to recall the whole channel with the vst easily. Different thing but very very helpful and fast!!