It certainly won't hurt, so I wouldn't discourage you from trying it to see whether or not it really makes any significant difference. It would be very intersting to see some back to back dyno pulls.

My understanding suggests that 'side gapping' won't make the spark any bigger as seems to be implied in the blurb. What it does do is to allow the 'flame kernel' to grow in it's very initial stages without having to 'grow' around the outer electrode, i.e. the outer electrode 'gets in the way' of the newly born and growing flame kernel to a slightly lesser degree than would be the case with an unmodded electrode.

This may result in a less 'deformed' early flame kernal that remains less 'deformed' as it grows and traverses across the combustion chamber. This may (or may not) result in a more efficient burn, but I have my doubts...