Here is a Sample and Spindump of a hang I have had a few times after pressing the Run button on the Script Editor window. Does not happen every time, but this just started happening with macOS 15.4, did not happen before upgrading.
Looks like the JavaScript runtime is not handing back control to the GarageSale. When this occurs again, can you please check if there’s any output from GarageSale in the macOS Console.app around the time of the lock up?