Hey computeroverhauls,
I apologize for the problems you have had trying to save your custom script, but if you save the script to the bin folder it will be erased when the environment closes. Unfortunately, anything not saved directly to the USB device (or other storage you may have connected) will be erased from memory when you leave Bootable Diagnostics.
In order to save a custom Bootable Diagnostics script for future use, you have to open the "scripts" folder in the "bin" directory and then save the file in the "usb_key" subdirectory.
I hope that this has answered your question, but please let me know if you have any other questions or issues.
Thanks,
Kris