You’re wrong about tungsten carbide masonry bits, I don't use anything else. Decent ones will drill through tiles with no problem at all, even porcelain; just keep the drill bit cool & don’t use the hammer action. But if you really want to waste your money on diamonds
As for plastic; like speedfit, I would not go anywhere near it particularly in my own property.
As for plastic; like speedfit, I would not go anywhere near it particularly in my own property.