I have a Birel with the same issue and have to purchase pads costing $70+ each. I tried other sintered pads but they last one run and actually burn up and separate from the backing plate. Don’t know about Tony karts, but assume it’s the same issue.
The Ferodo Kart attack are and excellent pad, They have great bite and modulation even when cold with no fade when hot with increased bite that can still be modulated. They have excellent wear characteristics too!