The 'show mouse cursor' selection turns on pointer trails option in the mouse control panel and sets it to the shortest trail length. I'm guessing those app do not like this option, it is a Windows 'feature' that is being use to make this work, not anything in NDI Scan Converter. Do you can do the same thing by turning off the 'show mouse cursor' option in Scan Converter, and then manually set these settings yourself.
krystal luncher
I just tried Galcon 2 myself, I'm able to see the mouse pointer on both the local screen and thru NDI Scan Converter.