The reason everyone is looking for power in these trucks is because they are tuned for gas mileage from the factory. In the case of an ignition coil, a sub standard oem part could leave unburnt fuel in the combustion process. I feel like Toyota would optimize the coils to get the best ignition possible from the spark plugs to ensure the best mileage possible.

Modern cars have pretty hot ignitions for this purpose. I remember putting the newer HEI distributors on my Chevy small block builds because they were cheap, could be found everywhere, and had a spark that was vastly improved over the seperate coil with points distributors in the previous generations.

The next big improvement was having a coil for each cylinder which is obviously what the 4Runner has today.
The 1GR-FE in our 5th gens has 10.4 to 1 compression with the Dual VVT-i to allow it to run on any octane fuel efficiently. So I would guess the coils are pretty hot right from the factory.
These guys could very well be on to something but it's hard to say without a lot of expensive testing to gather the data needed to compare.