Hi @NicoD
I'm not sure that it's a right solution you've been looking for but it works with my VIM 3 Pro.
See this topic on Khadas forum:
Twister OS Armbian 2.01 on VIM3! GL Acceleration Fan and AUDIO - Full HOWTO and Working Image DL
The details described in
UPDATE 2:
(In which audio works with correct ALSA configurations)