Home network with loops due to WiFi, precautions needed?

Solution 1:

This has however the effect that when the access points are close enough (depending on the local possibilities for setup), they can receive their partners' packets.

As a result, these wireless connections can be seen as additional connections (from the perspective of the network topology) that can cause loops in the topology

No, they don't cause loops, because the real link-layer header¹ of Wi-Fi frames has a flag bit that indicates whether the frame is from AP to client, or from client to AP. So even if the APs are all on the same channel (which they shouldn't be, if they are indeed close enough to hear each other) there won't be a loop because they'll just ignore all frames with the "From DS" flag.

Additionally, all Wi-Fi frames from clients are addressed to a specific BSSID. Under the hood, they have two destination MAC addresses – the "final" destination like in Ethernet, and the BSSID of the AP that the client is currently associated with.

(Similarly, frames from APs to clients are interpreted as having two source MAC addresses – the original source and the transmitting BSSID.) Note that this is not the same as the ESSID which is the textual "network name" – the BSSID is the specific AP's MAC address.

This also means that roaming is done explicitly in Wi-Fi – even if the client is in range of several APs, it will only send frames to only one of them, until it decides to disassociate from it and associate with another.

¹ Standard packet captures of a Wi-Fi interface will only show you an emulated Ethernet header (which is done by design; 802.11 is meant to provide an 802.2-compatible link layer). If you capture packets in monitor mode then you will see the real 802.11 header, as in these examples.