You don't need Apple to achieve wireless freedom, all you need is a few devices which can run OpenWRT. Use one of of them as router, the others as APs and you're set. The router can also be a virtual one, running in a container or VM on the server-under-the-stairs. The APs can be anything which you have laying around or managed to scrounge somewhere. This is what I do home on the range - farm really - where I have several APs spread around the area, connected together using Cat5 using a number of VLANs for different wireless networks: one for the private network, a guest network, an IoT network, an OPS network, a surveillance cam network and a low-speed open network called 'snigelnät' (Swedish for 'slug net'). The APs don't do routing, the virtual router of course does not do WiFi. Some of the APs are also connected to local POE switches for cameras. The whole setup has been mostly maintenance free since I got it up and running some 4 years ago, it offers way more functionality and flexibility than anything offered by commercial entities like Apple and it was cheap to build.