The short answer is, it depends. Sound is subjective, and to my ears, I can hear the difference if I lower the parameters for high gain targets. The less distorted the sound, the easier it is to train, so for clean or low distortion I might get away with lowering the parameters. But I want it to work as well as it can for any potential sound, so it’s my best guess based on limited testing on the hardware I have available. User feedback on what works and what doesn’t has helped a lot!
With the training, you’re trying to minimize loss, which is the difference between the predicted sound and the actual sound, so I can put a number value on the accuracy of the models. I also look at plots of the waveforms to visually see how close the sound is.