As I suspected, Nevryon doesn't key debounce. It's not something I can fix in the boot script as the files in question are repeatedly loaded from both Disc 1 and Disc 2. A possible solution is for me to reimage the discs with slow sectors, which might give the player enough time to lift the mouse button to workaround the issue.
However, all is not lost. Grab the latest obey.zip and the SA version from the dev site, I've detailed what changes need to be made in its boot script.
Regards the crash when loading a 2nd time, I've yet to investigate although suspect its an issue with the BASIC26 Module being terminated.