Yes, probably. It is possible to flash and use dasharo (a downstream fork of coreboot) onto a modern MSI Z790A motherboard, which gets you pcie gen 5, 14th gen intel, and so on. I’m not sure if the necessary code to get it running has been upstreamed into coreboot yet. https://docs.dasharo.com/unified/msi/overview/

From there, you can use corna’s me_cleaner to disable (and clean) the management engine. There are reports of it working on alder lake: https://docs.dasharo.com/unified/msi/overview/

Here’s a full tutorial on disabling your ME on modern systems: https://github.com/mostav02/Remove_IntelME_FPT?tab=readme-ov-file#neutralizing-me-and-flashing-via-fpt

To be honest, though, I wouldn’t bother unless you’re doing it for fun. I’m not sure if this entire process necessarily works on the Z790+14th gen intel anyway.

The BIOS does a lot less than you’d expect, it doesn’t really have an impact on gaming performance. For what it’s worth, I’ve been gaming in a VM for years, and it uses the TianoCore/OVMF/EDK2 firmware, and no issues. Once Linux is booted, it doesn’t really matter all that much. You’re not even allowed to use firmware services after the OS is booted, it’s only meant for bootloaders or simple applications. As long as all the hardware is initialized and configured properly it shouldn’t matter.