I don't know how the contemporaneous IRIS would compare for the target workloads but not necessarily faster than a stock NeXT, let alone one with whatever upgra

I don't know how the contemporaneous IRIS would compare for the target workloads but not necessarily faster than a stock NeXT, let alone one with whatever upgrades the customer wanted to stick in there. The 68000 and by that point the 56000 families both already likely had been proven for similar imaging workloads, with validated code available. At the same time the app dev story with interface builder etc on NeXT was pretty shiny. That compute was a direct component of the latency between something happening on the ground and photos reaching decision makers. In a post-glasnost post-Chernobyl environment with everything shifting around, very valuable to be able to upgrade that workflow rapidly. Someone who was in that group at Motorola in that era would know if there were any special-purpose 56000s that got sold.