I don’t think unraid and the IDRAC care about each other.

Good to know!

From my understanding flashing it will effectively remove the raid capabilities from the card, which then in turn allows Unraid to do its job effortlessly without the potential for weird issues arising, is that correct?

IT mode basically turns the card into an HBA, where it passes the disks through directly, instead of doing its own RAID.

I don’t know about BIOS settings off the top of my head, but once updated, you might consider resetting it to defaults, then going through them all. I’m sure there are some features Dell turns off by default in the name of compatibility.