Security is a big concern. Third-party patches might introduce vulnerabilities or remove certain security restrictions. The user should be aware that using non-official images can expose them to risks. They should verify the integrity of the image and the source's trustworthiness.
Performance-wise, maybe the image is optimized for KVM, leading to better throughput or lower latency compared to other virtualization methods. Features like acceleration for hardware offloading (like Intel VT-d, SR-IOV) might be enabled in the patched version to improve performance. fgtvm64kvmv721fbuild1254fortinetoutkvmqcow2 patched
Compatibility with other Fortinet products like FortiManager, FortiAnalyzer, or FortiCloud. The patched image should integrate the same as the official build if FortiOS compatibility is maintained. Security is a big concern
In terms of drawbacks, the main ones are lack of support, possible instability, and potential security issues. Also, updating such an image might be complicated if you can't apply official patches or if the patch has conflicts with updates. They should verify the integrity of the image