LMv2 is a cut-down version of NTLMv2 that was designed to allow for pass-though of NTLMv2-strength crypto when connecting old servers that expected a LanMan password or would cut the longer NTLMv2 password down.
It creates security issues like CVE-2019-1338 in Windows and has no place in the modern ecosystem.
Samba has not sent LMv2 responses in NTLMSSP since the BadLock fixes.
This makes it depend on "raw ntlmv2 auth" which also has the same issues.
The WIP branch I have at https://gitlab.com/samba-team/samba/-/merge_requests/1503 needs the knownfail entries updated (or tests tweaked) so it can be merged.