As many have already told you, you can contribute to OSM, I have put in it almost all the establishments in my area (Not at Big area but...). Although soon I have to update them

I Think so.

Yep, but if it only he need to remux then is less time than reencoding.

A few years ago was the Cryptomining today the IA

You can convertí the files in another playable format with Handbrake, probably you Won't need Change the codecs of the files only the container and the conversión will be fast than reencoding all