I had to read your post 3 times and still can’t grasp why you would resort to this.
At best, it’s an XY Problem. At worst, it’s a fundamental misunderstanding of how zigbee works, which leads you state that “it is a zigbee limitation that developers do not want to address because they feel it goes against the zigbee “philosophical theory”, but I think this is not correct”
First things first - you’re trying to work around the issue of HA being unavailable…by using an HA automation (which relies on HA being available). I don’t know what you did to test this, but it’s not gonna work.
Secondly, you’re assuming that if HA goes down, then Zigbee will go down with it. It might be true for ZHA, but is entirely possible to run Z2MQTT and MQTT on standalone hardware which runs independently from HA.
Third, you’re using a smart switch with smart bulbs. Fine, I get it - you want to enjoy the “RGB dimming fun” until the novelty wears out in a week. At the very least get a switch which supports decoupled mode so you can manually reset it back to normal switch mode if your zigbee mesh should die.
Fourth, what @fleskefjes was trying to tell you was that you don’t need Wifi smart switches - you just need to find a zigbee switch/bulb combination that support zigbee binding.
Finally, you’re trying to focus too hard on switching a router bulb into an end device, when Sengled bulbs were created as end devices for this specific purpose. They’re even mentioned further up in this thread, so all you had to do was scroll up and read instead of trying to reinvent the wheel.