https://www.mail-archive.com/openwrt-devel@lists.openwrt.org/msg41851.html
The wireless config section is kinda only up to layer 1.5, so
everything on netdev level has to be done in the network UCI config.
Example:config interface 'wireless0' option proto 'none' option mtu '1536'
Since this is not working in TOS it appears to be a bug