So, Mr Dinan appears to be saying that if you want your engine to make bigger numbers, you need to use the highest octane fuel you can lay your hands on.

The rest is induction and exhaust noise...

 

Back in the day I had BMW with M30 engine with Dinan chip in it, and with a custom tuner chip made specifically for my car based on dyno runs. Both were comparable, with custom chip being slightly better and substantially more expensive. This is goes back to old fuel maps tech, not very adaptable. I don't think modern cars can be improved in the same way. The following are my personal experiences with these chips:

1. Car becomes very sensitive to gas quality. It isn't just octane, you have to shop for top-shelf brands.
2. Idle goes to ****
3. Power gain was seat-of-the-pants noticeable only near red line
4. Marginal parts (fuel regulator, injectors) made it outright undrivable. This wasn't an issue until car aged past 4-5 years old.

In the end, I downgraded to stock chip and drove that car to astonishing 400,000km still with original head, block, cams, chain...