Question about Arctic Z2 Pro

I have an office desk with a cable duct at the back. When the tabletop is all the way back, there is 12 mm between the cable duct and the bottom edge of the tabletop. So that you have access to the channel when you move the top, there is approx. 4 cm space between the channel and the bottom edge. This means that the fixing screws should not protrude more than 4cm from the bottom edge of the panel. Does this fit with the bracket, it looks quite flat in the pictures? Or are there other suitable brackets? The duct also has a wall thickness of approx. 4cm at the back.