Questions regarding customizability of Kali drivers -- plus how-to?

tl;dr:

I want to add custom drivers to Kali which are loaded at start-up so that my wireless card just works like magic.

How do I do this?

Original Post:

I'm a fairly avid Linux user, however I have not gotten so deep as to start compiling my own kernel or creating custom distributions. So far I am limited to 10 years of experience running servers on Ubuntu and that's about it.

As I became interested in performing security audits on servers that I run I downloaded Kali and began to tool around with it. However as I became engrossed with Kali, I did what I always do and spent way too much time taking things just a little bit too far.

At the moment I have a USB flash drive (32 gigabytes) which has been tweaked out to look like a 28 GB ExFAT drive when plugged into a computer running Windows or Mac, however if plugged in during boot it will pull up Kali. (I had to do a lot of research, combine information from three different sources, and experiment a bit to find a solution that finally worked. If anyone is interested let me know and I'll post my steps)

The problem:

When booting from my live USB on my Macbook Pro Retina mid-2014 I run into issues with the drivers. The bigger issue is that WiFi doesn't work. At all. The wireless card goes entirely undetected. The secondary issue is that the resolution is jacked making it difficult to read anything.

With regards to the first issue, a bit of googling reveals that if you install Kali (as opposed to running it off of a USB) and if you plug in an ethernet cable so you have internet in order to perform this fix, then you can get WiFi working. It involves downloading linux headers and the Broadcom SDK and manually compiling the drivers.

That's neat, but remember that this is a live USB. I'm not supposed to be installing it and I don't want to recompile the drivers every time I turn it on. I also may not have access to ethernet in order to grab the linux headers and Broadcom SDK.

As a starting point I could compile the driver and put the compiled binary file on the storage partition of my flash drive. That way immediately after booting the USB drive I could copy the drivers over and start using them, but that seems a bit... manual and tedious. Ideally I would like these drivers to behave like all other drivers. I want them pre-built into the distribution, I want them to be detected and loaded at startup, and I want it to work like magic.

I'm also operating on the assumption that the specific version of Macbook I'm using might require different drivers. I make this assumption based on the fact that all answers I found online involve compiling the drivers instead of anyone linking to a pre-built binary. So a magical "just works" solution might require building SEVERAL VERSIONS of the drivers and putting them all in so it can detect and load the proper one.

The question:

This leads to my question: can this be done, and if so... how? How do I modify the Kali ISO to include additional WiFi drivers for the Macbook Pro? I tried googling and everything about creating custom ISOs seemed to involve just modifying configuration... how do you actually add drivers?