3:43pm 4th January 2017
This is most likely not a problem with the application or device you are running it on, it is more likely to be a slow DVD Player or a slow DVD itself, it might also be useful trying to distribute via other methods, such as making an installer and letting people download from a website, or selling USBs with the executable on. Another question, have you converted your electron app from source to executables? It is much faster and easier to start executables than it is to run the electron code from a command.
3:55pm 14th April 2017
I have a theory, it might have to do with the fact that you can't write to your typical DVD, so it may not be the load time, it might be that it's trying to write, and it can't.
I did a little investigation into my theory, and downloaded some electron apps, and then started investigating their package contents (on MacOS) to see if they were modified by the OS during the install process.
Most of the files I encountered had the same creation/modified date from when the app was packaged for deployment. However, in both of these cases, I noticed that inside the Contents/Frameworks there were three directories that were modified at the time I installed the app (Electron Framework.framework, Mantle.framework, ReactiveCocoa.framework, and Squirrel Framework).
It seems that if it tried to make those updates to those files on a DVD, there'd be an error.
That's my theory - it may not be correct, but haven't heard it mentioned here, so maybe look into that.