There are some useful entries in the /sys filesystem that are not covered by any of the existing interfaces, notably the "/sys/kernel/debug/ieee80211" tree.
Our motivating application uses the ath9k spectral analysis feature to provide detailed insight into what's going on in the Wi-Fi spectrum and infer sources of poor performance such as microwave ovens. In order to use this hardware capability, our application needs minimally write access to "/sys/kernel/debug/ieee80211/*/*/spectral_scan_ctl" and read access to "/sys/kernel/debug/ieee80211/*/*/spectral_scan0". Here is some documentation explaining how that works: https://wireless.wiki.kernel.org/en/users/drivers/ath9k/spectral_scan.
Conceivably, advanced networking applications may want access to other files in the "/sys/kernel/debug/ieee80211/" tree, so it may make sense to lump them together into some sort of "advanced-wireless" interface.
This request is made more pressing because, although devmode enables the functionality we need, it comes with a huge performance penalty. In devmode, our application's access to the spectral scan feature results in many thousands of system log messages (apparmor audit messages) that causes unacceptable CPU usage.
Note that in devmode you can (and should!) connect your interfaces to reduce the number of logged (but allowed) policy violations.