Finally I found why openldap's {lanman} hash doesn't work on my gentoo server... --with-lmpasswd configure param doesn't exist 'samba' use flag must switch-on --enable-lmpasswd instead.
Created attachment 119373 [details, diff] ebuild_diff
The net-nds/openldap-2.3.35-r1 ebuild (now stable) is affected too.
meh slipped through somehow, fixed as -r2 now. Thanks much for the report :)