Funck's novel approach to Grids Keyswitcher (with recent changes) does work for me for standard libraries and Kontakt!
The bigger problem becomes editing this controller data. It is clunky, having to hover the mouse over to automation edit point so that it displays what articulation you are at, and then going to the inspector panel to make a change where the controllers amount is now listed by its percentage and not the articulation name.
An even bigger problem is not being able to easily make fine movements in tempo mapping because the range is not customizable, you can't draw clean natural curves. No midi comping or nested takes means you will end up with a thousand takes of midi clips littering your time line, and you need to remember where they are to drag them in to position for A/Bing. Lastly no video support.
I'm not sure I follow the first part of what you are saying? haha
The point of this workaround is basically having something better than nothing in Bitwig, which was to just input keyswitch notes way down at the bottom of your piano roll and having to constantly cross reference what note triggers which type of articulation from a notepad or the VSTI interface itself. With this method you can at least just hit a shortcut to whip up the INDEX automation lane of the FX selector, then drag the index automation points up/down and choose from the list it goes thru.
It works really well for me. Robismz was having issues still because they have a "lookahead" option on their VSTI that doesn't play nice with it, but otherwise this should work fine with most VSTI's that have keyswitching.
There is the other perks with this workaround where we now have the proper articulations playing back from any playback position, where with traditional notes input into the piano roll, it has to playback those notes from the piano roll before the sampler knows to switch to that articulation. You can now move your playhead start position or rewind/fast forward and it's always going to play back the correct articulations (like starting playback midway through a long held out note if you have note catch turned on.)
I agree with everything else you say tho in the second half. I still use Pro Tools for post production/video stuff. If you are needing massive Orchestral VSTI templates for 10,000 queue scoring jobs to video, Bitwig is not the best tool for this. There is no video, no smooth tempo mapping, no timecode, no anchor points, and a whole list of things making Bitwig inadequate for post production and super large Orchestral productions compared to your other options.
My VSTI Orchestral use is pretty much limited to adding some light strings, winds, and brass to pop music productions, in which case this workaround has been doing great for me. I've been using it for a few months now with no issues. If I feel a production I am working on can use some strings on it, I just whip up these Bitwig Chain patches I set up with these workarounds and get to playing them like it were any other synth, only now editing the articulations is all set up and isn't a giant archaic PIA haha.
Bitwig has been an amazing match for the way I approach composition and sound design, and it's a great match for the type of stuff that I compose, which is mostly in the electronic music/pop genre side of things. It's definitely not the right tool for alot of users out there, yet. It is slowly adapting to having things professionals would need in other aspects of music production; for example in the newest beta for v5.2 they have added many editing features taken directly from Pro Tools audio editing, something I was very very pleased to see as a 25+ year Pro Tools veteran.
There are some neat things you can do tho pertaining to the sound design of Orchestral stuff. There was someone in the Bitwig discord spending the last few days using Bitwig's modulators to vary up the way every single note plays back from his VSTI, essentially inventing his own "infinite round robin" where that didn't exist in the VSTI at all, and the results did indeed sound more realistic. Neat stuff like "creating features your existing VST's didn't have" is something that is easy to do in Bitwig.
-edit- I forgot to add that I also agree that the lack of MIDI comping or something like the playlists that Pro Tools has is pretty cumbersome in Bitwig. I don't use the clip launcher to compose in Bitwig, but I have found a way of utilizing it to drag over clips from the arrange window and store "takes/playlists" over there because of how Bitwig has the feature of having the clip launcher integrated with the arrangement window compared to Ableton and others were clip launchers are on their own separate "island." Again, not the best, but it is a bit of a functional workaround.
Cheers