How to set separate IP address ranges for IOT and Guest networks ORBI 770

Orbi systems have an interesting history.

The Internet of Things (IoT) WiFi network is Netgear's response to over six years of frustration expressed by customers when they purchased WiFi devices which were very difficult (or impossible) to connect to their Orbi system because the smartphone app was poorly written.  While over 90% of IoT devices "just connect", those irritating few devices caused users to howl:

• I want to be able to assign different names to the 2.4G and 5G WiFi (like I did with my old Nighthawk router).
• I want to be able to (temporarily) turn off the 5G WiFi so that devices will connect at 2.4G because it is the only WiFi that exists (at that instant).
• Netgear's response for six years was, "Nope.  Live with it. Find a work around. Or get rid of it.  We're not changing anything.)
• (In those days, nobody ever asked, "let me separate IoT devices from the rest of the network.)

Finally, adding another WiFi network (IoT) that (a) can have a different name than the primary WiFi, and (b) can be temporarily turned on/off is Netgear's solution.  Sound familiar?

Likewise, the original Orbi realized there were two reasons to have a Guest WiFi network:

• To be able to grant someone access to the network without sharing the WiFi credentials used by all the devices in the house.  Have someone over who wants to hook up their tablet?  No problem.  After they leave, the Guest WiFi password can be changed and not affect anything else.
• To be able to separate some devices from the rest of the network.

The original Orbi product had an option: Let devices on the Guest network interact with the primary network, or not let them interact.  Some Guest wants to print something out.  Cool.  No problem.  Enable access and then (after they leave), turn it back off again. When the AX products were introduced, that option went away.  Guest needs to print?  Tell them the password to the primary WiFi.  (not cool)