@cv66seabear Sorry about the problem you ran into. The Snapmakerjs version 2.5.2 is quite slow and we are going to fix the problem, but it will need some time. Before that we suggest you use the older version like V2.4 at Downloads and Updates.
Regarding the USB drive issue,please format the USB drive in windows system(not in MAC OS) and i think the problem will be solved. Please don’t hesitate to tell us if you have any problem.