Torque Converter Blackmagic "is it stalling me out"

Does the Sniper-2 have a DFCO (Decel Fuel Cut-Off) feature like all OEM fuel control systems do? If it does, I would think the RPM or speed to re-enable fuel would be a calibration value that you could adjust.

What you are describing sounds like DFCO that is not re-enabling in time (i.e. turning the injector(s) back on) and simply stalling out the engine. That being said, OEM systems also have the torque converter clutch ("lockup") and other variables to work with to get the coast to a stop engine control right. I am totally unfamiliar with these aftermarket systems as I worked on/with the OEM stuff for too many years!