I've got a new computer. Long story short, I swapped a Titan GPU for a GTX 1080Ti (MSI, Aero). Running on the Titan the processing in Step 2 was slower than with my old laptop - but it ran.
After replacing the GPU, while the computer appears to function normally doing everything else, while Pix4D crashes almost immediately in step 2 (Step 1 it completed). I switched down to 4.1.15 in hopes of the older version functioning with the replaced (downgraded) GPU... no luck.
There have been no substantive changes to the computer aside from the GPU replacement. That Pix4D has been unable to work with a higher end GPU is frustrating. That it is unstable now is even more so. I have a large - for me potentially critical - project pending and I need to know I can process data.