Routing service in Preset

I would like to have the routing service switchable via Preset.

Reason is the following:

For me GraphHopper has a better routing than brouter.

For planing online GraphHopper is fine but I can't use it outside because of bad cell coverage. Problem is offline GraphHopper doesn't support NoGo areas. So I must use brouter outside.

The result off all restrictions is:

Planing: online GraphHopper

Outside: brouter