I don't have a eye one spectrometer, but before I start mailing stuff around:
I printed two inkseperation.tif files using QTR calibration mode on standard copy paper. One was printed via photoshop (following the instructions), the other was printed via the QTR print tool. They look absolutely identical.
This suggests there's something going on when using QTR tool in 16bit with the paper curve, or that QTR print tool's approach is that much different than printing from PS. So to check again I printed two of the same files, one through PS, one through QTR tool.
They're close, but again, the blacks are really different out of QTR. Were's the thing, in a way the QTR file looks better, or smoother (so maybe I'm just used to Photoshop crunching the file?), but the problem is the photoshop print does more closely represent what's on my screen (almost pure black). And I'm on a calibrated NEC panel.
I tried to upload scans, but couldn't get it to work, so going to email them to you. The shirt in the scan is between 95-99% ink load depending where I eyedrop it. The PS print is close to this. The QTR print looks great, but realistically is a lot brighter.
Seeing these let me know if you'd still like me to print and mail you a step wedge. I'm happy to do it, but I'm just confused why Photoshop is more accurate and so different than the QTR tool.