Thread devices on different network become unresponsive because HomePods are interferring

Setup

• 2 WIFI networks, each with their own internet gateway, each with their own wifi base stations
• These WIFI networks are close to each other (house network and van in garage of house)
• The 2 different "homes" defined in the Home application share the same AppleID
• The first network has 5 HomePods, the second one has 2 HomePods
• The first network has one stereo pair
• The second network has the 2 HomePods also configured as a stereo pair
• The second network has an AppleTV 4K (1st gen)
• The first network has no AppleTV
• All HomePods are on 17.1.1 and have recently all been factory reset (in attempt to resolve problem)
• 11 Thread devices on first network, they are from different vendors and have all received their latest firmware updates
• The second network has no thread devices.

Symptoms

• All thread devices on the first network become unavailable in HomeKit shortly ( 1 to 5 minutes) after the HomePods on the first network are powered on.
• This situation doesn't resolve itself, there is no "self healing". This continues for as long as the HomePods on the first network are powered on.
• When the HomePods in the second network are powered off, the Thread devices on the first network become available again, gradually ( 1-5 minutes).

What has been done already in an attempt to resolve the problem, but did not (completely) work

• Cut power, restart everything, remove devices, add devices again.
• Disable auto-join 1st network on iPhone with same AppleID. This caused the HomePods in the 2nd network not to switch randomly to the 1st network anymore, but the problem remains.
• Configure 1st network WIFI base station not to accept connections from HomePods on 2nd network, based on their MAC address. With auto-join first network, this causes problems with the 2nd network HomePods, as they freeze when trying to join the blocked network. Without auto-join first network, the problem seems to have been resolved, but a (smaller) number of Thread devices on the first network still have the symptoms described above.

What resolves the problem but is just a temporary solution

Park the van (2nd network) far enough away from the house (1ste network). Everything works perfectly then on both networks.

Assumptions

• Toggle WIFI network auto-join on iPhone synchronises to all iCloud devices with the same AppleID. I saw it changed on the Macs, after I changed it on the iPhone.
• The HomePods are switching randomly from the first to the second network, even when the WIFI signal in the van is close to 100%. Since the 2nd network is using StarLink, I think they might switch (even just one of the stereo pair) when StarLink internet gateway outages occur, or when the dishy is switched off to save power. Not really sure if disabling auto-join solves that completely.
• The HomePods are interferring using Bluetooth, which might explain smaller amount of Thread devices on 2nd network having problems when WIFI is compleltely blocked to them. This also seems to correspond considering the (shorter) Bluetooth range versus the blocked devices.

Question

Can these problems be escalated to someone at Apple who can have them fixed?

Proposed changes

• Make WIFI network auto-join a "per device" choice, not something synced over all devices. This includes making the option available in the user interface of HomePod and AppleTV.
• Switching WIFI networks on an iPhone when the internet connection does not happen automatically generates a dialog and the iPhone user can choose what should happen. I fear this is decided automatically on a HomePod and it just switches WIFI network. Please make it an option in the user interface of the HomePod and the AppleTV not to do that.
• The HomePod is negotiating with WIFI devices which are not part of its "original" network (maybe after a short network switch), making these devices unavailable on their own network. This can be avoided by making the previous 2 points a reality.
• The HomePod seems to be scanning for Thread devices over Bluetooth. In the setup described above this is undesireable. Not exactly the scanning part, but the part where it negotiates with these devices and makes them unavailable in the network when they were already configured. Disabling Thread Bluetooth scanning might be an option to have on the HomePod, or some additional query to see if the devices is already set up.
• As an alternative to the 2 bullets above, the simple option to disable Thread completely on the HomePods will already solve the issue for situation where no Thread is needed in the "original" network.