@olivernoah Thank you for your answer and for your encouragement. You are the only one has answered me and gave a path to resolve my problem. In Batocera forums I've not such luck.
By now I've got working the Realtek RTL2832 DVB device: I've noted that .ko files needed (included module dependencies) I use from another distro with upper kernel release are valid in an environment with a lower kernel release (6.x). In fact this should be fine for TBS device but althought I compile against the Batocera kernel release it cannot load the module due to several issues related with symbols and kernel versions I'll troubleshoot later.
With a problem solved next I do is run NextPVR backend. It does with an specific .NET runtime for Linux and it runs fine and can discover DVB devices but it lacks of many software dependencies like libraries and dtv-tables to fully work. These dependencies could be installed from pacman but it shouldn't be like this (documentation also points this) and it "floods" the entire system with files and libraries that could be not necessary.
I'm searching for more self-contained PVR backend solution.
Of course nothing of these could be possible without the overlay system.
I'm keeping look for ... I think the solution for Batocera will be the same for Recalbox.
Regards.