I've discovered the main arseache with skirting surface mount boxes since we just moved in: modern plugs with integrated strain relief and bulkier adapters won't fit because they foul on the floor.
The french ones are just for the cables you still run the cable up to the socket on the wall. Those type remind me of an IT room with the cables and sockets at waist height.
I've got round that by fitting the sockets upside down.
I've discovered the main arseache with skirting surface mount boxes since we just moved in: modern plugs with integrated strain relief and bulkier adapters won't fit because they foul on the floor.