NAT64 GW with jool but without prefix delegation

After successful using that instructions

to get an IPv6 only LAN/WLAN behind an openwrt router my question is:
Is it also possible to use it without an extra prefix from the uplink?

(SLAAC only, similar to relay modes)
At least RAs (DNS option, PREF64 option) have to be changed.

Yes, NAT64 can be combined with NAT66 and work with just ULA.

You can test it and reply here.

But what's the use case? If the uplink has a proper v6 prefix delegation it should be used.

I have different uplinks.
That with prefix delegation is the most comfortable.

But my idea is also to use it mobile:
Telekom, Vodafone, Telefonica and Freifunk provide only a /64 - directly on interface, without DHCPv6 PD.

I forget to mention I still want use GUA.
I consider NAT66 as evil. (NPT too, sorry)
ULA is only used instead of ipv4 between router and clients (DNS resolver, webgui and ssh)

You can use use ULA and NPT (network prefix translation) to avoid nat66.

Edit: but yes if you have a mobile or other shity uplink with only a single /64 then a relay or nat66 is needed...