Just wanted to toss out my experience for anyone NOT registered on this forum who may read this thread.
TL;DR
This did improve/increase torque on my parents' old 1994 Ranger compared to before swapping the wires, when I did this about a year or two ago. These are old vehicles with aging components, and it's worth a shot if you find the 4 cylinder underwhelming.
Regardless of what people may say, because it's fun to pretend like we know it all, in my case this did work and it's been helpful with drivability, including backing out of the driveway. The truck is mechanically maintained, without being ridiculous. Installing a new ignition and electrical system, to alleviate a 20+ year old system's potentially (likely) weakened spark, is not a worthwhile cost in this case, although if my parents were Ranger enthusiasts, it may be. It received new plugs and wires, which were a welcome improvement (by keyboard warrior logic, this shouldn't make a difference either, because a spark is a spark), but I was still disappointed with the improvement, so I swapped around the wires and things improved a bit more. I imagine this change brought the power output closer to brand new condition in 1993/1994. If you're someone out there wanting to squeeze a little bit more out of these terribly weak and old engines, this is worth a shot and you can always revert to the original, pointless configuration unless you think a 90s vehicle's biggest emission/usability issue is keeping a second spark plug firing on the exhaust stroke.
Side note: I have a 1993 rx-7 and it too has dual plugs and disconnecting the "waste spark" plug (trailing plug) results in worse performance, because it fires the trailing plug during the combustion as well as the exhaust portion of the cycle. It'll run with one, but not nearly as well. "64k should be enough memory for anyone". Not looking to argue, just sharing info for the readers rather than the posters, and encouraging an open mind--if you have an old Ranger, you very well may bring a little more life to it. If you don't notice details, also depending on the engine's performance, you may not notice a difference. If you don't notice air conditioning's power consumption on engines, you certainly won't notice this, but even if you do, it depends on your sensitivity to change and susceptibility to the placebo effect. I've done things looking to improve/restore performance on various vehicles and not felt an anticipated change, which was a waste of time and money, but this was a great improvement in our case.
The Ranger's 4cylinder is so underwhelming, and maybe this wouldn't have made as noticeable of a difference 20+ years ago, when brand new, but it absolutely makes a difference now despite the small cylinder diameter.
EDIT: Just saw the last post about aircraft. He may be referring to rotary engines there as well since some small aircraft use rotaries, but if it's a piston engine, that's a new and interesting fact to know!