Some UK members are doing something similar by putting a box or a blank over an existing UK switch and then mounting the battery operated POPP switch on top of that.
These are working with a community-created device handler.
Device handler for the UK switches:
One of the project threads on building the Popp into a blanking cover:
The Z wave.me, popp, and devolo switches all use the same device handler. They typically cost around ÂŁ40. Each of the four corners can be depressed independently so you get multiple functionality. These are only available on the UK zwave frequency.
Follow-on questions on these devices should be asked in One of the threads above. But I just wanted to mention their availability as a UK option for a similar use case to the linear smart switch cover.