Apple's T2 Security Chip gets itself in the way as much as possible when attempting to install Linux on a Mid 2019 Macbook Pro and a lot of the available documentation for Linux-on-the-mac online is pre-T2. After quite a bit of back and forth and eventually finding the right resources I managed to get Ubuntu installed on my MacBook Pro with everything working... except the microphone.
Initial Success and Failure
Getting started with this process was a bit of a minefield. The first resource I came across was How to Install and Dual-Boot Linux and macOS, an extremely detailed and useful documentation piece with one minor caveat (that I didn't take heed of initially):
As of right now, you cannot install Linux on the internal SSD of a newer MacBook Pro or Mac Pro (2018 or later). You can still install on an external drive, however.
Despite the warning I did manage to eventually cobble together a working base Ubuntu install using Ubuntu 20.04, a bootable USB-C drive (notably: not a USB-A adapter), and rEFInd. In the end I had a functional Ubuntu installation on the same internal SSD as my macOS install but none of the peripherals (keyboard …