If you're looking for a guide on using i1Profiler, I can suggest some general resources:

I can provide a step-by-step guide on how to set up a completely free, professional-grade calibration workflow for your exact system.

The demand for this specific version doesn't stem from a desire to avoid an upgrade fee. Instead, it's about legacy hardware support. and newer removed support for the older i1Pro revision 1 (i1Pro 1) spectrophotometer , leaving users of this device unable to use newer versions of the software. This has left many with a valuable but incompatible measurement device, prompting them to seek out the last compatible version, 3.1.1.