PITR mechanism does not allow the user to choose which snapshot to use as base before replaying the oplog. Given that Atlas does not validate the snapshots after they have been taken, the user ends up needing to setup their own validation process. That alone is not a problem. However, when one needs to use the PITR mechanism, not being able to select a previously validated snapshot may lead for PITR restores to use unvalidated snapshots.

Either Atlas should enable, uppon choosing, the validation of snapshots right after they are taken, or allow the selection of valid snapshots (snapshots taken within the range of the PITR window) to be used for PITR restores.

Without these there is no way for the user to know if the PITR mechanism reliable, and you do not want to find out it is not when you really need to restore.