Yeah, didn't look into this for a while, but now that we all have more time I come back to this.....
In-between I have set up samba.conf so that the media directories can be accessed as guest with read only for alle devices in the house and those directories and including some for storing my backups need to be accessed for r/w as user root. Thats enough for my needs.
But now I wanted to use the big disks I have in the LE box also for storing my Timemachine backup from the two iMacs I have here....!!
No way to configure samba with e.g. "vfs objects" options. I think that this is not included in LE ?
Anyhow I made some tests with Netatalk in a docker container and after some experiments it worked quite nice. Only difficulty was to carefully start and stop the container at boot and shutdown. The easiest way was to use a wrapper like the Linuxserver.io addons use. So I ended up with a nice add-on in a zip-file that handles everything carefully. Very handy now :-))