These stops are designed for a specific set of countersink bits sold on AliExpress. I know these are bits for routers, but it's cheap and works great with drills.

https://www.aliexpress.us/item/3256804616582641.html

Note: The sizes described on the stop files are from the start from where the countersink blade meets the bit. Also, to protect the part that touches the wood surface, glue on a metal washer with epoxy. Depending on the washer thickness, choose one with a greater countersink depth that will reach the correct depth you need once you add the washer to it.