I have tested out NHRPv6 on FRR as well and found out that it seems impossible to get it work.

Sorry for late reply. It probably don't but I haven't had time to test it yet. It's not a big issue anyway.

for me on VyOS 1.5-rolling-202503030030 it works if you first remove the ospf configuration, then delete the protocols:

I'm just sharing my thoughts here: Could it have something to do with the fact that the IPv4 prefix is a /32? why does it have to be a /32 anyway (when NHRP is configured)? On Cisco IOS there is no such restrictions.

I can see that on VyOS 1.5-rolling-202503030030, the network type "point-to-multipoint" and "non-broadcast" is available. But not "point-to-multipoint non-broadcast"

vyos@LBS-RO1# set protocols ospf int eth1 network 
Possible completions:
   broadcast            Broadcast network type
   non-broadcast        Non-broadcast network type
   point-to-multipoint  Point-to-multipoint network type
   point-to-point       Point-to-point network type

vyos@LBS-RO1# set protocols ospf int eth1 network point-to-multipoint 
Possible completions:
  <Enter>       Execute the current command

It is possible to configure from FRR: