The only feature it doesn't provide is literal IPv4 resource access (meaning http://220.127.116.11
or something like that and the fix is to just create an A record).
Of course, until Mikrotik implements at least stateless NAT64 in RouterOS, this is all a pipe dream, but to illustrate why it would be great - here's an example of how 464XLAT makes life great.
If you've deployed 464XLAT, you can crack that nut with stateless NAT64 in the CPE. (except for IPv6-only hosts in the LAN - see end of post)
Suppose each CPE has multiple /64 blocks to play with (which is recommended practice anyway) - let's say /60 for the sake of argument using the longest nibble-boundary prefix shorter than 64.
Let's say you have 2001:db8:cafe::/60
assigned to a CPE.
You could easily designate a /96 for local 4->6 stateful nat outbound.
to avoid conflict with any LANs, earmark the entire ....F::/64 block.
More specifically, any internal IPv4 addresses behind the router would be mapped to:
(where a,b,c,d ~ hex of the IPv4's 4 octets)
On the ISP side, you would have a similar dedicated stateful NAT64 prefix. You could use a ULA prefix, or even burn one from your public block if you're worried about customer firewalls blocking fd::/8 as a destination prefix... suppose you mapped 2001:db8:64::/96
on the ISP side as the "Internet"
On each CPE, you'd have stateless NAT64 as follows:
DSTNAT64 a.b.c.d -> 2001:db8:64::aabb:ccdd
SRCNAT64 a.b.c.d -> 2001:cafe:f::aabb:ccdd
On the carrier side, you'd route 2001:db8:64::/96
to your CGNAT box(es), and they would statefully SRCNAT to some public IPv4 address in their pool for 64 translation. Replies would automatically be directed to whatever CPE device had originated the socket - the original src would be 2001:db8:cafe:f::aabb:ccdd
- and the CPE would statelessly map this back to the private IP.
With this in place, the CPE would allow dual-stacked devices on the LAN to reach IPv4 literals w/o any need for DNS64 (or even legacy devices w/o any IPv6 support whatsoever). At this point, DNS64 is only required for IPv6-only hosts in the LAN which need to reach IPv4-only hosts on the Internet - DNS64 would map into that same 2001:db8:64::/96 space. Obviously a 6-only host would not be able to reach an IPv4 literal (as you stated in your post) - but given this 464XLAT scenario, there's no reason not to dual-stack behind the CPE router.