Cork can be difficult to cut reliably, and it chars like crazy. If I were doing it I would buy precut cork rounds and engrave them.
Like:
or any number of cork providers on aliexpress:
30 rounds for a dollar.
https://www.aliexpress.us/item/3256807135504718.html
Granted those are barebones, but the labor saving alone is worth it.
More refined, 10/$0.99:
https://www.aliexpress.us/item/3256806147910728.html
More refined, like the ones I used in that project, 6 for a buck:
https://www.aliexpress.us/item/3256806079529732.html
Maybe you want square? 50 for about 5 bucks:
https://www.aliexpress.us/item/3256808320340262.html
Granted, all of these prices are probably introductory rates, but cheap is cheap.