After 9 months of waiting for a simple clean experience from Q10Pro, I had to break the piggy bank and buy a different product.
Zappiti sounded to me like the right one. And it does delivers exactly what I need: a friendly user interface, crisp 4k, it speaks with 2 NASs over Samba, it does resume paused movies, excellent subtitle support out of the box. Clearly a more expensive choice, but there's little out-there one can choose from. Especially Kodi free alternatives.
At any moment I wasn't looking for a media player that I have to ssh into to make it play movies, I wasn't looking for a confusing Kodi/external player experience.
So Q10Pro will be sold for penny in the next few days or send as a gift to people willing to struggle with it. I stopped hoping obvious bugs will be fixed by Himedia. Either they don't understand, either they are victim of their own past decisions. But clearly they have plenty of debatable software choices they made with no logic whatsoever (excluding nfs from wrapper, never a decent subtitle setup or language detection and users here knows it).