Race condition with hotplug.d/ieee80211/11_fix_wifi_mac

Ubiquiti U6+, like many other devices, uses a hotplug script to assign wireless MAC addresses (usually derived from MTD or LAN interface).

Recently, while testing snapshot on Ubiquiti U6+, @bmork noticed incorrect wireless MAC addresses in certain cases. Since I couldn't reproduce this on my U6+, we did some investigation and ran into what looks like a race condition involving hotplug.

It appears that wireless interface initialization is not synchronous with hotplug.d/ieee80211/11_fix_wifi_mac, and thus any delay in hotplug processing prevents the wireless interfaces from picking up the correct MAC addresses. Instead, the interfaces presume LAA MAC addresses, which doesn't prevent wireless from operating but is unexpected behavior.

Since any hotplug change affects all devices, I'm asking for guidance on the best way to go about fixing this, or if I'm even looking in the right place.