mtx261

It worked! I did the exact modifications OP did to the MXM slot. Laptop booted, installed drivers, and even ran some games without issue. Interestingly, my T2000 reports as a T2000 Max-Q, a lower-powered variant with a 40 watt TDP (lower then the 60w R9 M270x it's replacing). Temps seemed quite good despite the cooler not being mounted properly at all (need to get nuts for cooler). The 4700MQ in my system seems to be a great match for it too. You might get more power with an older gaming laptop GPU, but I think this provides plenty of performance while also being power efficient and not requiring any weird software hacks to get working. Now I just need to put everything back together...

Very interested in seeing if I can get this working as well. I managed to find a Quadro T2000 for $75 on eBay, so we'll see how it goes. I have two M4800s, so I'll see if I can compare the performance of them too.