You are correct the issue is the wifi power strips can connect to either
Then back to poor design. Most of their products are 2.4 GHz but their wifi strips do both?? Then there is absolutely no reason that the 5 GHz radio shouldn't have simple "disable" feature. Problem solved.
band but to communicate with the Hydros controllers the way they communicate they have to be on 2.4ghz and the same channel as the Hydros controllers are on.
See above, it is LAZY deign.
So even if the Hydros controllers did do 5ghz the wifi strips and the controller would still need to be on the same channel to communicate with each other. Most IOT devices do not communicate locally but this was done so if internet is lost as long a wifi is still good
It sounds like there may be some confusion about how TCP/IP works. Any device on the same subnet can communicate, regardless of SSID or WiFi channel. That behavior is completely independent of 2.4 vs. 5 GHz.
If these devices are meshing using the same SSID as your home network, that introduces all kinds of potential problems unless the meshing is extremely well engineered. However, even with solid engineering, it’s poor or lazy design not to give users the option to lock dual-band devices to 2.4 GHz. Period.
If they actually behave the way you're describing, I’d bet a lot of the “network issues” people report are related to Spanning Tree Protocol, route cost confusion, and improper mesh behavior. Mesh networks can be a nightmare when poorly designed. SONOS is a textbook example of poor mesh implementation. They designed network devices without understanding ST P and that has led to two decades of network headaches that still aren't fully resolved because they backed themselves into a compatibility corner.
the controller can still control the wifi device without having internet. The only issue with that is some ISP provided routers will also quit if there is not ISP connection. So ISP provided routers may not be a good idea.
I am not aware of any "ISP" router that "quits" (shuts down Wifi) when there is a loss of internet. The "router" routes traffic form the LAN to the WAN -- it has nothing to do with "wifi". The DHCP server runs on the LAN interface and has nothing to do with "routing" or "wifi". Unplug the network cable and your WiFi and DHCP services chug along happily.
The "fault" or "issue" here is that shared SSIDs are EXTREMELY COMMON. Hydros can/could EASILY handle that fact by either selecting a single band (2.4 GHz or 5 Ghz) for their products, or allowing those will dual band radios to have a radio selector.
You're a nice guy -- but spinning every shortcoming of the product as some kind of benefit is no different than Carlos and David trying to spin DRM-locked reagent as a benefit to ensure quality.