The mechanism to attach the tools iso to a VM grabs the name and verify's the signature file. If it is a windows machine simply swapping the files out will still load the windows.iso when attaching tools to a VM.
I have not tried this, though this option should work without issue.
Thank you for your answer.
I would be happy if there was a documented official way to do this.
Everything points to just replacing the files should work but without having actual official documentation/statements to back this up it feels experimental and maybe dangerous in a production environment.
When you replace the VMware Tools bundles in the shared product locker, as of ESXi 6.5 the hosts scan for updated tools every 5 minutes as opposed to only when VMs power on. An alert will be displayed if a newer version of tools are found. Source: What's New in VMware vSphere 6.5 whitepaper (PDF), page 15.