In this example the Route10 would be the router directly connected to the ISP demarc.
Route10 would get it’s IPv6 address via SLAAC from the upstream router, a /64. ISP DHCP server delegates a /56 prefix.
Then each vlan internal would have it’s own /64 out of the /56 delegation.
My home “lab” is always in flux. Like I was saying before, I tend to test things for work ( at the ISP ) on myself at home. When I was deploying CGNAT, I had cgnat, which is when I started pushing ipv6, when we started deploying multi-gig xgs pon, tested that on myself as well. In that test my router changed a few times, I tried the Calix GS4237 which is a combo residential gateway and ONT, and then I went to a two-box solution with an indoor 10G ONT. I built a pfsense router with 10G connections, then eventually moved to a mikrotik, and now soon a route10.