If you are running an older environment that requires 6.2.x compatibility, Build 1010 (6.2.2) is a standard point-release. However, it has been superseded by numerous updates in the 6.2.x branch (up to 6.2.17) that addressed security vulnerabilities and bugs.
Achieving “better” requires understanding that FortiGate on KVM is sensitive to: fgt vm64 kvmv6build1010fortinetoutkvmzip better
: The compressed archive containing the deployment files (like the .qcow2 disk image). Quick Reference for Deployment If you are running an older environment that requires 6
(Data Plane Development Kit) to minimize latency and maximize packet processing by bypassing standard virtualization overhead. Resource Scaling fgt vm64 kvmv6build1010fortinetoutkvmzip better
While 6.2.2 is an older, established build, it is significantly outdated compared to current stable branches like End of Engineering Support: