I use glass tiles as the front panels,
Whatever you do don't forget goggles I guarantee you will regret it if you forget to wear them even once!The powder from the drill is another issue its gets in your skin like fiberglass and keep it away from food and pets..But you already know that
I only drill 10mm holes though and mount the controls behind on a copper plate.
I mark out with masking tape about 3 or 4 layers thick so the drill doesn't slip.
Diamond tip drill and be very patient.
I tape the tile to a wooden block bigger than the glass then you can hold the glass by holding the block.
You can ty-rap it by drilling holes either side of the glass in the wood.
To cut through hole for tubes better trying a granite worktop cutters maybe they can do it?
The only other way is heat the glass and cut the holes with a hot punch.
I.e. soft glass and hot punch.
But watch out hot glass the glass doesn't look hot and you can easily forget and touch it!The other way is a local glass student!
Regards
M. Gregg