Unrefined coconut oil in the modern day is not the same as homemade coconut oil or a coconut oil of 100-150 years ago.
Breakdown of the fat to free fatty acids and later development of rancidity happens several ways. The abiotic oxidation you mention, NAPD, is only one route. Hydrolysis (reaction with water) is another. Bacterial oxidation is yet a third. The more impurities in a fat, such as water, protein, other organic contaminants, trace metals, dirt, etc., the higher the chances of the fat breaking down and faster development of rancidity. This is more likely in a homemade product than in a commercially produced product.
"...what does the ROE do to help..."
It is an antioxidant, Taleman. It prevents oxidation.
I'm not saying making homemade coconut oil shouldn't or can't be done. Just understand the issues before you leap into action, so you know what you need to do to make the best product you can. People who render lard and tallow at home have many of the same issues to consider, and many of them do fine. Like I said before, I would keep the product refrigerated and use an effective antioxidant such as ROE.