This page has the answer you seek:
https://github.com/Amerikranian/Finger- … n-Version/

@2
You might submit prs upstream to wherever has a maintainer documenting this.

If you wanted to be really fun and clever you could also become the maintainer of accessible_output3, which wraps accessible_output2, catches this exception, and prints an informative error about what to do. I'm not kidding.  This is, let's call it a 70% serious suggestion.  It's a 100% serious suggestion if you just go work out how to bind Tolk with cython, put the entire package under the lgpl (which works as long as it's in 100% cython because reasons), stattically link the NVDA controller client and Tolk itself, and put it on Pypi (at which point this goes away and we also avoid the DLL hell problem).

@5
accessible_output2 isn't.  Lucia is. I'm not sure who else might be relevant; I'm not tightly coupled to the modern Python ecosystem.

@7
If you want details on this I can give them to you, but broadly speaking you depend on accessible_output2 for linux and/or mac, and provide a uniform API on top.  Then for Windows you compile the Cython version against multiple versions of Python, run a couple commands, and up to Pypi they go.  If you get interested reach out, I can concoct Appveyor scripts for your releases by cannibalizing what I have to do for Synthizer anyway and explain what specifically is going on with the licensing that makes Cython advantageous as well.

Off-topic, but I saw the developer of soundRTS uses his own patched accessible_output2 https://github.com/soundmud/accessible_output2