Yeah the second rule is: for anything that runs locally and for which your use doesn't require an internet connection: put it on a separate network without WAN access.
I also had to learn that lesson painfully when my network connected Brother printer got a (unasked for and unapproved) firmware update that disabled the 3rd party toner cartridge it was using. It's now blocked from the internet in my router, but it's unfortunately a case of shutting the barn door after the cows are gone.
Hue bulbs and strips run fine on HA. For a couple of reasons, I have a completely offline system running in a Docker container with a ZigBee dongle (mainly I have no control over my LAN). I don't use the bridge any more. You don't get some of the scenes and other functionality that the bridge offers, but 90% of the functionality is there.
The bridge already has some weird requirements like refusing to work unless you connect an ethernet cable. As far as I know the update is to force you to use an account with the app, but the devices should still be compliant with other controllers.
Thankfully it's not much of a loss, and there's actually a lot to gain by not touching Philip's cloud.
If you use HomeAssistant and have some Philips Hue equipment, you can pick up a $30 coordinator and you'll be in full control. It's a nice bonus that compatibility with other zigbee devices expands dramatically.
No, they're just enforcing that everyone must have an account to use the Hue app. But big parts of the whole Hue ecosystem depend on local access, so it's out of the question that they'd remove it.
And I don't know if it's just me, but responsiveness seems worse in recent months (using iOS app, don't know if it's the app or the bulbs or the hub). And sometimes the app is out of sync with the actual light states. I haven't seen this in years of using Hue bulbs and app.
Plus finding I'm logged out and having to log back in when I just want to turn a light on/off in the middle of the night (because baby) is a PITA.
I haven't had Hue login troubles, but the quality of the light control has gone down a bit. If I tell it to turn the lights to the fireplace mode, that gets turned into multiple instructions to the light bulbs, but sometimes it drops some of them for no reason. So I get half-brightness daylight-white instead.
Yeah that sounds about right, too. Sometimes I move the slider and it doesn't adjust. Sometimes the slider is in one place and jumps to another without me touching it. Not often, but I'm pretty sure it never used to happen.
I'm probably going to ditch Hue in favour of smart switches and dumb bulbs in my next house, so not too worried about it.