From Slither's upgradeability checks.

We can try to detect issues with parent initializer calls, concretely whether they are 1) missing, 2) duplicate, or 3) incorrectly linearized.

The main question is how we detect what is an initializer function. We could look for an initializer modifier, or for functions with name initialize, or for the naming convention used by Contracts Ethereum Package (soon Contracts Upgrade Safe) which is something like __ContractName_init.