I've been running a custom router for about a decade, but I too have haven't tried handling the wifi on my own. It's always been easy to get an external access point and there's a bit of a guarantee that it's done correctly.

I kind of feel like that's cheating though; I've outsourced the hardest part of the project to someone else. Maybe one of these days I'll take an old NUC or something and buy a decent wifi antenna for it and try and do it properly.

[1] Initially pfsense, then OpnSense, then ClearOS, and now some custom firewall rules in NixOS.

So it's been awhile but the best and simplest way I think is use an access point. I don't want my wireless gear doing routing. From a logic stand point they acts as wireless "bridge" to the physical network, and nothing more. DHCP, etc. stay handled in one place for the entire network, back on the physical router.