So a simpler solution would be to use enode.io which now supports BYD vehicles (but getting production access is not very straight forward - I’m still waiting 3 weeks out) using the custom enode HA integration, fortunately evlinkha.se also supports BYD vehicles (not listed, but I just confirmed this while setting up the integration) through enode’s API.
The only drawback with evlinkha.se is it costs money after the 30 day trial and the limits are quite severe on the free account, not really viable for anything in scope.
So happy trails everyone!