I don't have an answer for you since I have not been in your position. However, files do have "associations" and you may want to load a disc, cancel out your software (Macgo) then use the "get info" to see which files are associated with Macgo and change them. The question is what app to change them to universally. (I wonder if you could point it to a script that does pretty much nothing.) Alternatively, you might see if Macgo has a process that exists during your start up and cancel it out before loading a disc and see if that works.
Is there anything in the Macgo preferences that lets you choose to not open the disc?
Wish I had better advise but this is where I would start.