Thanks so much for everyone who chipped in on this thread, especially
@HermanTX . All 3 of my Pentair VSP's are working great in my Jandy iAquaLink. The biggest thing I struggled with was finally realizing that the pumps need to be wired to the always-on-power side of the physical relay, so that the pump's control panels are always on, and the other thing I struggled with at first was realizing that the pump #'s shown on the VSP setup page in the iAqualink software correlate to the actual pump addresses that I set on the physical Pentair units (addresses 1, 2, and 3) and that I no longer am actually using a physical relay to turn those pumps on like my older fixed-speed Jandy pumps.
I set my main Pentair filter pump to 1750rpms for now (prime at 2500 for 1 minute), and then for my Slide pump and Disappearing Edge pump, I set 3 different pump speeds for each pump, Low (950), Medium (1750) and High (2750), and assigned the Medium speed on each of those two pumps to an available Aux (5 and 7 respectively), so now I can either automatically turn them on to Medium speed, via a) the daily schedule, or b) manually with a push of an icon in the iAqualink... and I can also change the pump speeds on them to Low or High manually too. It's really awesome and I really love these pumps.
Also really love how the Jandy Status page shows me the current RPM as well at the Wattage drawn, very helpful.
I have 3 more Jandy single speed pumps, but one is a 1.0HP pump so it doesn't draw a ton of power, and the others are beefy Jandy 3.0HP pumps to run the waterfalls but, ROI on those would take forever cause I only run those waterfalls about 4 hours a week in total.
This change to VSP is one of the best things I've done with my pool equipment and setup!