Ok so I double checked.
Its 60mm between the screws in the wall (same as UK I guess).
The plate itself is 84mmx84mm.
The depth of the switch (naked without the outer layer) is about 10mm.
With your solution I could still use the raw “naked” switch underneath the philip hue dimmer through the hole. A standard UK one should be good.
The depth of the plastic cover that goes onto the wall is about 11mm (a bit curved so difficult to measure) and goes out a bit further.
Here are some more pictures.
Recommendations?
