I know absolutely FA about electronics so don't even know if this question makes sense.
Is it possible to add a manual rotary knob to replace / augment the touch screen control to alter the scale of the satnav map? In the same way as the radio sound knob alters the voice level on the satnav.
The reason is I find the touchscreen control too random and fiddly.
If it is possible, I would much appreciate a brief description or specification that I could take to a an expert technician, and say "do that".

Have you experimented with the settings in the dual screen mode.

Allows you to have a fixed scale (right hand) map running alongside the interactive (left hand) navigational map. FL2 XS SD4 Auto 2010 2012-2017 (21k - 91k miles) (MY2011)
FL2 Metropolis SD4 Auto 2014 2017- (16k - 76k+ miles) (MY2015)