I tried something similar one time but not on ESXi. Two ports can’t have the same IP address so I created an /etc/hosts file so each host knew about the other based on hostname and not ip address.

I had the same issue, only using a 930-8i w/ 2M cache. Honestly performance sucked on all of my VMs. I reinstalled the server with Rocky Linux 8.8 and KVM using the same array and performance was acceptable (the array was configured as a LVM volume). I then added a NVMe drive as a LVM cache and performance was much better (good enough for my homelab). Too bad, since I really prefer VMware.

What about power to an alarm? What is the output voltage of that power supply?

You really don’t want to do this. Read up on how ftp uses random ports and is not really secure and you will quickly change your mind. A good alternative is SFTP, part of SSH. It uses the same port and is much more secure.

Are you looking for software that can run on an installed OS to emulate the PXE bootloader that is normally in the NIC firmware? If so, I’m not sure one exists. Even the name Preboot Execution Environment implies this happens before an OS is running.