Need guidelines regarding ulogd configuring

Hi all,
My question is a bit strange, because I do not have any issues with operation, but configuration still seems strange to me. I have configured nftables to work with ulogd. Everything works just fine, but check the following command and it's result:

root@LEDE:/# cat /proc/net/netfilter/nf_log
0 NONE (nfnetlink_log)
1 NONE (nfnetlink_log)
2 NONE (nfnetlink_log)
3 NONE (nfnetlink_log)
4 NONE (nfnetlink_log)
5 NONE (nfnetlink_log)
6 NONE (nfnetlink_log)
7 NONE (nfnetlink_log)
8 NONE (nfnetlink_log)
9 NONE (nfnetlink_log)
10 NONE (nfnetlink_log)
11 NONE (nfnetlink_log)
12 NONE (nfnetlink_log)

As far as I understand, some of the numbers (protocol families) should not be NONE, at least family number 2 shall have nfnetlink_log instead of NONE. Anyway, everything is working correctly, and I do not understand the meaning of /proc/net/netfilter/nf_log. It clearly shows that I have nfnetlik_log module available for IPv4 (family number 2), but is is not loaded (NONE). Nonetheless it works. Is it something obsolete and the file is still used for backward compatibility or is it somethings else?
Would be great to hear some good thoughts about this case.