Support for DHCPv6 Prefix Delegation Only

I tried to see if there were existing issues and I did not see any that were active.

I am using a Fedora IoT installation with NetworkManager as a router. My ISP has recently started deploying IPv6 utilizing DHCPv6 Prefix Delegation only and delegating a /56 prefix through DHCPv6 but without providing a Global Unicast Address (GUA) for the WAN interface. I have multiple active VLAN's that I would like to allocate /64's from the delegated /56 prefix to.

As best as I can tell since the initial DHCPv6 request includes the IA_NA and IA_PD options, but since it does not get a successful IA_NA response, the received prefix is discarded.

Is it possible to add options to only request a prefix (along with a hint for the size) for the WAN interface and distribute it to other interfaces on the system?

I am using NetworkManager-1.38.4-1.fc36.x86_64 currently but switched to systemd-networkd to get a working IPv6 setup for the time being (although NetworkManager is my preference).

Here are the systemd-networkd configurations I am using successfully with my ISP.

# cat wan.network 
[Match]
Name=enp3s0

[Network]
DHCP=yes
DNS=1.1.1.2
DNS=1.0.0.2
IPv6AcceptRA=yes
ConfigureWithoutCarrier=true
KeepConfiguration=dhcp-on-stop

[DHCPv4]
UseDNS=false

[DHCPv6]
PrefixDelegationHint=::/56
WithoutRA=solicit

# cat lan.network 
[Match]
Name=enp4s0

[Network]
VLAN=solar
VLAN=iot
VLAN=enp4s0.172
VLAN=guest

DHCP=no
DHCPPrefixDelegation=yes
IPv6SendRA=yes
IPv6AcceptRA=no
Address=192.168.100.1/24
ConfigureWithoutCarrier=yes
IPForward=yes

[DHCPPrefixDelegation]
UplinkInterface=enp3s0
SubnetId=1
Announce=yes

# cat iot.network 
[Match]
Name=iot
Type=vlan

[Network]
Description=iot vlan
DHCPPrefixDelegation=yes
IPv6SendRA=yes
IPv6AcceptRA=no
ConfigureWithoutCarrier=yes
IPForward=yes

[Address]
Address=192.168.101.1/24

[DHCPPrefixDelegation]
UplinkInterface=enp3s0
SubnetId=2
Announce=yes