Correct, what RFC2317 brings you, is an example of you creating a new namespace in some structured format (IIRC, there are three different example formats given in this RFC), and you just have the upstream ISP, which has the reverse delegation done on the zone cut boundary for the IP ranges it controls inserting a CNAME out to your new namespace on nameservers you control for the reverse PTRs so the reverse PTRs can be formed that way.
Running a long time ISP, I found extremely few customers wanting to do something like RFC2317, or could actually figure out and do it effectively. Almost all were content with control panel/API and having the ISP do it after I pointed them to this informational RFC asking them if this is what they wanted.
Note, the CIDR RFC didn't come out until Sep 1993. Thus even brand new network equipment in the mid 1990's were still very classful.
And even then, knowledge of how to properly use /etc/netmasks in SunOS v4.x (or the equivalent if some other network stack even had one) was very scarce.
In the mid 90's, SMBs connecting to the Internet would have very typically obtained a /24 from their ISP, and had direct connection online, no firewalls, barely any proxy servers (although that was popular for some mid sized customers that would have needed multiple /24s or even a /16 to get all their workstations online).
It wasn't until the company Network Translation, with the PIX came about that anybody even considered doing private IP address in general as a firewall strategy with NAT translation using private IPs. And then it took years and years to become popular. Long bought by Cisco at that point.
I don't think Cisco IOS even had NAT until something like 10.2, when it was a premium license package.
Sure plenty of solutions out there, but its all going to be Enterprise priced. $600-$700 an AP, plus whatever is going to be the controller. In this space, you'll find cloud based options, controller based options, and standalone.
If you are willing to go this price range, I think FortiAPs feeding back to a Fortigate FW is rock solid solution. But a FortiAP-431F is $616. And a base FG60F as controller is $535 + service if you need it. And although you probably won't need repair options, support/maintenance is a yearly fee ontop of that.
Ubiquity was definately a unique company offering many of the enterprise features for consumer pricing.