FINALLYYY after a day and a half I got it to work. A couple notes to hopefully help along someone else:
Not all USB drives work, some just suck. I first tried a low budget thumb drive I had lying around and I could not boot into DOS via the drive, no matter what I tried. After that, I used another drive and it worked immediately. Go figure
For me, my computer would not boot past the Lenovo logo while the thumb drive was installed. I had to first boot into UEFI using F2, then when loaded I could insert the drive.
Though it may seem like common sense to most... the FPT_windows file should be used to make your backup(like the instructions suggest), but when you format the thumb drive per the directions, you have to remember that you formatted it for DOS so you need put the DOS version of FPT on your thumb drive. (dumb mistake I made and quickly fixed)
Additionally regarding the above: when you're using the DOS version of FPT(on your thumb drive), you'll need to grab the FPTparts file as well and if you had to use the special FPTparts file dealing with Error 104, don't forget to use that same FPTparts file on your thumb drive. (I'm assuming this matters, but feel free to correct me.
A step that's probably seen as common sense but not mentioned in the first post: once in UEFI bios and after inserting the thumb drive, you need to then navigate to the BOOT tab, change Boot Mode to Legacy Support, change Boot Priority to Legacy First, and make sure USB Boot is Enabled. After this you can hit F10 to save/exit and you will automatically boot into DOS on the thumb drive if everything went according to plan.
Much trial and error and hours of thinking I broke everything went into this process because some of the things mentioned above weren't mentioned in this thread. If most people know these things then COOL, I'm happy for you, but if not, I hope this can help someone who might be stuck and frustrated.