Chosen Solution
I have linux installed on this macbook and wifi performance is appalling. I wanted to replace the card but before I waste money, is there anything in the hardware/firmware that would prevent it from working with another card than the original apple one?
Not really beneficial ;-{ First you are limited by the physical size and the number and size of antennas the system offers. I would focus on your WiFi access point (AP). Where are you in relationship of the AP are you using a mesh setup? Or using a WiFi repeater which is not properly setup? If you really need speed, you really need an Ethernet connection! WiFi even WiFi6 is is not as fast as wired connection. Don’t forget the host you are trying to connect to has limits on its connection to the internet (and your access too) unless you have a local system and then its connection is then important.
You probably should use macOS. I used it on my Unibody MacBook Pro from the same year and it worked great. If you expect performance issues, enable low resolution mode within performance hogging apps. To answer your question, I could do it on a 2014 MacBook Air if I wanted to, why would an earlier Pro be different.
