1. nftables supports NPTv6 (Network Prefix Translation), which is similar to NAT, except it's stateless and every device remains individually addressable. So you can configure your DHCPv6/SLAAC to assign to each device both an address from your globally-routable prefix and from your ULA prefix, and then NPTv6 will handle mapping your ULA prefix to/from the internet.
2. Lots of ISPs only assign a /64 by default, but if you configure your router to request a /56 via DHCPv6 prefix delegation, you'll usually get the larger prefix.
FWIW, I'm using both of these on my home network, via a router running OpenWRT.
2. Lots of ISPs only assign a /64 by default, but if you configure your router to request a /56 via DHCPv6 prefix delegation, you'll usually get the larger prefix.
FWIW, I'm using both of these on my home network, via a router running OpenWRT.