Sierra MC7710 on xx30

[Garlic Bread]

I am trying to make a Sierra AirPrime MC7710 WWAN card work on my Thinkpad T430s, and if I have any luck I'll install another MC7710 in my X230. However, I am running into problems at every turn and now I turn to you.

For starters, I run Windows 10 21H2 IoT LTSC on my Thinkpads for compatibility without bloat. I have installed the Build 5087 driver with USB compositions 0, 2, 4 and 5, deleting and clean installing the driver every time, focusing on the COM5 port where the MC7710 shows up in device manager. After installation I get a Code 28 (Unknown device) from device manager, and I have encountered the KERNEL_MODE_HEAP_CORRUPTION BSOD a few times. Sierra Skylight consistently says "Sierra Wireless device not detected". I have tried multiple MC7710 cards on multiple xx30 Thinkpads (All jailbroken with 1vyrain), and come to the conclusion that mu hardware is fine but that I must be doing something wrong. I know for a fact that some of you have made the MC7710 work on xx30 Thinkpads, and I being unable to replicate your success I must ask of you to please share your wisdom.

How did you do it? What driver version is the correct one? What USB composition mode did you opt for? What am I missing here?