ESXi (kernel) boot options can be added during ESXi boot up (by pressing SHIFT+O) or by updating the ESXi boot.cfg configuration to influence specific configurations and/or behaviors.
In the past, it was difficult to get visibility across your fleet of ESXi hosts on which hosts might be using custom boot options, especially in cases where you might not need them anymore or worse if someone has manually added a configuration that you did not intend.
In vSphere 8.0 Update 3, a new bootCommandLine property has been added to the vSphere API and can now provide full visibility into all boot options used for a given ESXi host.
PowerCLI 13.3 had also GA'ed yesterday, which supports latest APIs introduced in both vSphere 8.0 Update 3 and VMware Cloud Foundation (VCF) 5.2 and you can easily access this new property by running the following command:
(Get-VMHost).ExtensionData.Hardware.SystemInfo
Thanks for the comment!