Thank you for the pleasant responses from those my guide has helped.
Unfortunately I do not have any other help to offer for the “recent” follow up questions. I do not use any 3rd party Matter/ Thread devices as of yet. The whole point of doing this last year was to get an ESP32-C6 to connect to Thread, and as a quick proof of concept, I enabled the RGB LED on it and had it show up/ played with it in HA.
Today, I updated HA and all relevant integrations/ apps including: Matter, OTBR, and ESPHome Builder. My ESP32-C6 with RGB LED still works.
My limited research suggests that using iOS devices to connect a 3rd party Thread device to your HA OTBR remains a finicky process
“and the fundamental problem is that Apple’s Thread credential management in iOS is opaque, with no user-facing way to inspect or purge stale entries from the keychain.”
@kitus you received a response here, I hope it helps you: Thread Border Router (ZBT-2) and iOS: "Thread network credentials does not match with any of the active thread networks around" - #10 by wmaker