That would be a nice temporary option.
Even better if the function could check for active connections and keep wlan on in that case, like keep streaming music in the background. Or even wait for it to finish streaming with 30 sec timeout and then switch off. I would not need much more and could be considered as security feature .

Jolla looking into hardware adation sure depends on money as motiviation. As chen wrote here "we pay them licence, they will do the software and SW optimisation, and future updates", i conclude it is a quite linear relation between how many tablets chen sells and jolla having justification to put manpower into optimization?