#IPv6 #ULA isn't a bad idea. Since providers hardly ship static prefixes I even believe that it should be deployed in mostly every network. It may coexist to static or dynamic prefixes.
It makes you independent of what IP addresses you get from your provider. You can route between sites.
When I listened to this talk for me it felt like there is no real use case for it, but it is. Stop using A records whatsoever. #lPv4 is dead.
https://packetpushers.net/podcast/ipv6-buzz-107-ipv6-unique-local-addresses-at-ietf-114/