Everything what you did seems OK. SX Ultrastar is known to work with universal SX driver and it looks, that there is some issue on USB communication level. My only idea is to turn libusb logging on by inserting
Been a little while, but I think I finally figured it out. I have been using a linux VM to develop and test code. After hitting a few more walls I realized I had never tried running the code on a native linux machine. I had assumed that since the program was getting the PID and a handle to the camera successfully that it couldn't be the VM's fault because otherwise I wouldn't have gotten that far. But as a sanity check I tried running the indi-sx driver code on my raspberry pi zero, and it worked perfectly! I'm not sure what the problem is, but having the program run through a virtual machine seems to be the reason why the camera commands were failing.
Yeah, I was indeed working with Virtualbox. I didn't think that the vm was the problem though because I was getting the device descriptor and whatnot just fine, I even got a GET_ENDPOINT_STATUS control transfer to successfully execute. I figured if the vm was going to be an issue then nothing would work at all. But I stand corrected haha. Thank you for your patience and help with all of this, I really appreciate it!