I guess it depends on what you call "minimal". From my experience if you do deep squats regularly...YOU WILL UNDOUBTEDLY increase the strength and function of many muscle groups of your lower extremes, including the pubococcygeus muscle which among other functions is responsible for creating the back pressure necessary to ejaculate by it's reflex contractions.
If when you ejaculate, you experience 2 or 3 major shots and the rest just drops off the end of your cock it's because your PC muscle isn't conditioned enough to provide the continuously strong reflex action to shoot the rest out. That is a matter of simple physiology. The stronger, more conditioned a muscle is the longer it can perform at a high rate.
Kegal exercises are designed to strengthen the PC muscle. However, deep squats where you squeeze while going up effectively is doing the same exercise with the added effect of recruiting more muscle groups and increasing overall ***** flow which is essential to any muscle development.
Some people genetically have more developed muscle groups than others, the PC muscle is no different. With this specific aspect of the subject, North's ejaculations are genetic. In some people under-developed PC muscles are linked directly to urinary incontinence. But just as people improve the strength of their PC muscle to help with UI (bed wetting), improving the strength of it increases it's performance with it's other functions.
The volume of your load is based primarily on the amount of time you give your testes to produce semen. But it is conditional also based on your hydration and sufficient levels of stored zinc. Sufficient protein is also necessary to improve hypothalamus and pituitary function...which control hormones. Hormones which allow the testes to produce more semen during arousal.
In my specific case I increased my volume by 2 more steady streams and about 3 or 4 additional spurts. That is a noticeable difference that I wouldn't consider "minimal".
Undoubtedly, you can increase the size of your ejaculations through diet and exercise, but ultimately, those are marginal improvements at best. You're not going to go out and do kegels and suddenly start spurting a small lake, it just doesn't happen.
If they did, I seriously doubt:
A. This conversation would be taking place.
B. Anyone would consider Peter North as having an above average load, because we'd all be able to do it.
Yes, not ejaculating for a while will increase the volume of the load, but there is a limit, as in, when the testicles receive the signal that the ideal amount of sperm is ready. That varies from person to person, strictly due to genetics. The average male ejaculation ranges from 2 to 6 mL, meaning having Peter North like ejaculations is rare, because he's just genetically different. (I sound like Brucie from GTA IV).