I have found this one to be a big help and generally the one that really slows down smart defense! this is SK31200 in the checkpoint knowledge portal!
In web security, put <HTTP Protocol Inspection> | <ASCI Only Response
Headers> to monitor only AND set the "protection Scope" to < Apply to
connections related to URI resources>.
SK31200
1. High CPU use caused by configuration applying to many
connections
Symptoms:
Traffic through the Security Gateway may be
connections>slower than expected, particularly HTTP traffic.
Traffic through VPNs may also run slower than expected.
Traffic performance increases and CPU use drops significantly, after setting SmartDefense HTTP Protocol Inspection to apply only to connections related to resources.