This is fascinating to me. I used Cisco wireless for several years and read the documentation enough to know about why 802.11k sped up roaming so much, but never put together that requiring a scan across the entire spectrum is an inherent design flaw.
The complete lack of network-driven roaming, which AFAIK is still missing from wifi 6/E, must be frustrating to large-scale network designers and admins.
Also frustrating when we were doing indoor WiFi positioning at Apple. Scanning 2.4ghz - super fast. Scanning 5ghz takes forever. You need repeated scans as quickly as possible to converge your position (at least the way we were doing it at that time)
The complete lack of network-driven roaming, which AFAIK is still missing from wifi 6/E, must be frustrating to large-scale network designers and admins.