Safe to delete an extra EFI 'system' partition? Win10

Question

I have an extra EFI partition left over on a hard disk (Disk 0) from a mistaken windows install when I built my computer. I have since reinstalled windows onto my SSD (Disk 1) used command prompt tools to move the boot manager files / recovery partition onto my SSD (Disk 1).

I have successfully removed the leftover recovery partition from Old Disk (Disk 0) and have verified using REAGENTC \INFO command that my current recovery partition in use is on my new SSD (Disk 1).

Now, I still have a 100 MB EFI 'System' partition on Old Disk (Disk 0), and I also have another 100 MB EFI 'Hidden' Partition on SSD (Disk 1). I have verified using System Information and DiskPart AND bcdedit that my system is booting from Volume 4 which is the 100 MB EFI partition on SSD (Disk 1). I also have my BIOS currently set to boot from the SSD (Disk 1).

SO--- In theory-- I should be able to delete the old 100 MB EFI Partition on Old Disk (Disk 0) and not experience any crazy boot issues yes?

My IT friend assures me I can as long as I made sure I'm currently booting from the new EFI partition which it appears (through System Information, diskpart 'detail disk' command, and bcdedit command) that I can safely delete the old EFI partition.

Has anyone had experience with a case similar to mine? I have done a lot of research and almost everything says basically don't delete the EFI partition (even if it's now 'extra'?).

TLDR; Is it safe to delete the EFI partition on the Old Disk (Disk 1) which does not seem to be used for my boot currently (system shows I am using the 100 MB EFI partition on new Disk, Disk 1, to boot)?

Answer 1

My advice? Make an image of that partition first using something like clonezilla. Just in case you need to restore it. Then delete the partition and do a cold reboot. If you can still boot up... go ahead and resize your partitions to use the freed space.

You've done your due diligence. What you've checked indicates you would be safe to do so. But backups are how you make deletion of anything actually safe. And if two decades as a computer tech have taught me nothing else? Always have a fallback. Multiple, if possible.