Huh, this is kinda wild. So for esxi images, this would seem to beat/potentially be simpler than the traditional Packer + interacting with an ISO on esxi infra, yes?
Arguably yes. I think the big improvement is that an upgrade is really just switching from image A to image B, rather than dozens to hundreds of individual package transactions. Furthermore parts of the system are fully mutable (e.g. /etc) allowing you to run automation against a system post install for more customisation.