well if you have a detailed blueprint you can get anything in a custom order, depending on difficulty an the size of your bank account.
well no i don't believe additional routing is done for mini toggles this would be custom work probably preformed by a hand router, in a rear route application the the route is very large and there is plenty of space for extra controls in there. if you wanted a different location on the guitar with a rear route a cover would need to be made you would probably get a les paul cover or something, and there is a big question of if they can drill a wire channel to it or not. on fender style stuff with a pick guard there is little room but a mini togle can be squeezed in and any location under the pick guard could be done fairly easily.
so:
what type guitar?
where do you want it?
and
are you good with blueprints and drawings? it may be easier to just have a skilled tech do the work.