If you use netlink operations directly,

Thanks for such feedback.

Should this programming interface become better known?

you can have the kernel filter on various criteria
and only get the socket entries you are interested in.

This is good to know.

This whole discussion has zero to do with what text format 'ss' outputs.

Some software components are affected here.

The socket statistic tool is using data from the directory “/proc/net”.

* Provided text files refer to known Linux data formats.
  Can it happen to work with other data formats there?

* The analysis program can also be extended for the support
  of additional data formats, can't it?

Regards,
Markus