>        I don't know if the following is something I've missed or
>        if I've just caught a bad time to cvs update:
>
		[opt_ns stanza]

Uh, AFAIK those are supposed to work either way.  (I left them
separate because I'm thinking about defaulted INET and/or NS when NSIP
is turned on).  Provided you fix the opt_compat_netbsd.h thing, either
one stanza (e.g., opt_nfs_boot.h) or two stanzas should work.
It does for me.

I'd guess either your config(8) is out-of-date, or you cvs update'd at
a bad time.