I'm going to experiment with your suggestions a bit now, I always used to tap the Clima "button" without realising tapping the temp would do the same thing!I take your point on the touch controls, but personally I've not found it an issue if almost 3 years of driving.
The temp display on the main screen is always lit, and the temperature touch control never moves - it's always directly under the temperature display.
I find, in the odd move away from 21°, that a tap serves better than a slide. Each tap moves the temp 0.5°.
Also, if you tap the temperature display you get the attached screenshot and you can adjust the lit temp control there.
I've got by until now but only considered the voice option because it's on offer, thank you for your help, very insightful to know how others use the controls.