I think the manual is behind:
$ unwind -nvf/dev/null
preference { DoT oDoT-forwarder forwarder recursor oDoT-dhcp dhcp stub }
OK?
Index: unwind.conf.5
===================================================================
RCS file: /cvs/src/sbin/unwind/unwind.conf.5,v
retrieving revision 1.24
diff -u -p -r1.24 unwind.conf.5
--- unwind.conf.5 29 Oct 2020 17:28:12 -0000 1.24
+++ unwind.conf.5 26 Dec 2020 16:48:59 -0000
@@ -123,7 +123,7 @@ itself recursively resolves names.
.El
.Pp
The default preference is
-.Ic DoT forwarder recursor dhcp stub .
+.Ic DoT oDoT-forwarder forwarder recursor oDoT-dhcp dhcp stub .
.It Ic force Oo Cm accept bogus Oc Ar type Brq Ar name ...
Force resolving of
.Ar name
