For anyone interested in the protection circuits used by Keeppower (widely considered the gold-standard of Protected 18650 cells), there is a lovely thread I just found here by RMM of Mtn Electronics:
https://budgetlightforum.com/t/-/22519
This is a teardown with pictures of the Panasonic NCR18650B cell as wrapped by Keeppower and EVVA; with the inclusion of their Seiko protection circuits and button-tops.
It would be great to see something similar with other brands/re-wraps, as obviously not all protections are made equal...
Hirsh