Sometimes if I am only using my Virus IT 61 I select it as audio interface in Ableton and then connect the Outputs of the Virus to it's own inputs, with that I can use it incl. Midi and it works quite well.
I'm surprised you got that to work since Apple discontinued support for HAL plugins in Catalina.
But the method you're describing is the same principle as just using a normal audio interface for the analog outs though. Nothing new.
This does not fix the midi timing problem. This is a problem with the VirusVC plugin. When using the plugin, your host can't send midi directly to the virus. Only through the plugin.