Reference:https://supportcenter.checkpoint.com/supportcenter/portal?
eventSubmit_doGoviewsolutiondetails=&solutionid=sk97638

These users are created by default and cannot be deleted:

SecureXL is an acceleration solution that maximizes performance of the Firewall and does not compromise security. When SecureXL is enabled on a Security Gateway, some CPU intensive operations are processed by virtualized software instead of the Firewall kernel. The Firewall can inspect and process connections more efficiently and accelerate throughput and connection rates. These are the SecureXL traffic flows:
Slow path - Packets and connections that are inspected by the Firewall and are not processed by SecureXL.
Accelerated path - Packets and connections that are offloaded to SecureXL and are not processed by the Firewall.
Medium path - Packets that require deeper inspection cannot use the accelerated path. It is not necessary for the Firewall to inspect these packets, they can be offloaded and do not use the slow path. For example, packets that are inspected by IPS cannot use the accelerated path and can be offloaded to the IPS PSL (Passive Streaming Library). SecureXL processes these packets more quickly than packets on the slow path.
Reference: https://sc1.checkpoint.com/documents/R76/CP_R76_Firewall_WebAdmin/92711.htm

(Should be "migrate import")
"migrate import" Restores backed up configuration for R80 version, in previous versions the command was " upgrade_import ".