Funny how Harley's had the same coil output/plug arrangement for decades and were not concerned that one of the plugs was not transferring electrons in the "correct" direction..I'll stand by my original post, it doesn't matter.
What is easiest for routing wires to the terminals would suggest which wire goes to the top and bottom.

 

Opps should said dual fire tho..

 

wasted spark wave form. notice that the strike is mostly positive but when the wasted chamber collects enough gases, it will reverse or negative fire. if it were as you say, the spark could not decisively ignite the cyl under compression. the cyl under charge creates an environment conducive for the gas to ionize and create electrical path for the spark. notice the intensity of the wasted spark discharge.
your are getting off tangent.
coil of modern era are diff mainly in the ability to provide more energy to over come the 70's era. the chamber still fires around the same voltage level but the newer coil will go beyond by over coming resistance, aka, if the plug fires at 8k and resistance builds, they can go up to what their rating is for ex. 50k.
more and more coils are auto transformer types where primary and secondary share the same winding.

 

When you get spark you have spark across both cylinders at the same time.. Looks like your sampling O scope does not have enough band width.. What scope are you using? What's it's sample rate.
Wasted spark will have a lower fire voltage as chamber pressure is lower. Not sure what you mean about wasted chamber collecting gasses and firing later.. What coil are you using? Looking at the waveform, shouldn't every other spark change in magnitude. One peak should be higher than the next and the other cylinder should show the opposite?

 

there are many styles of coils. each has its own signature matter of fact, a trained tech can tell you if it is a ford, gm or volks.
the above is from archive i have
your example of the era coil is not correct.
while compression does have a certain role in helping the excitation of fuel molecule, it has zilch for the electrical side as it is the electrical side that shreds apart the molecular level that ionizes the fuel so current can flow. the same as lightning, if the air did not ionize, the strike cannot happen.
as far as the mexican beans, kill the heater circuit on a vacuum tube, taint gona work.
now, not every cylinder will fire everytime so you can get a combustible mixture on the exhaust stroke. being it the exhaust, not much can happen but it does show up in a very low percentile of lost power. there is also overlap and exh reversion that can keep some mixture from voiding the chamber.
if you have a tuner, throw it on and watch live data, many miss-fires but if it does not cross a threshold, the ecu ignores it, but we are talking 70's era.
you cannot use one coil to define others, it has to be apples to apples.

 

Well.. You need to put on your technicians hat and look a little deeper.

Figure 1 Not sure what that is other than a way to calculate mutual inductance.
Figure 2 It's OK.
Figure 3 It's only OK if a wire is added like in the updated pick.
Figure 4 Has an error. If both coils are wired to give positive output, you won't get any spark across either coil. The voltage will be the same across both coils and no net current flow.. Kirchhoff's voltage law.

HDs are not wired that way anyway. My schematic is correct. The schematic I posted came from the DTT websight. I'd put more faith in Chris Schroeder (RIP) than what you show for sure.

http://www.daytona-twintec.com/tech_ignition.html

It don't make any difference which way the electrons flow in a plug. It does in high current apps like DC tig welding but for a spark plug the actual energy is low.

You're theory about heating the cathode of a vacuum tube does not apply here. In that case the cathode needs heat to emit electrons because there ain't any/many atoms in the tube to knock electrons free from. That is why they call it a vacuum tube. Again, lower cylinder pressure sparks at lower voltage which is why you don't see the high voltage at the plug.. Your "excitation of fuel molecule" is in the weeds. It takes more voltage to jump the gap on the cylinder under compression. It's the main reason some like to close the gap on higher compression motors. Makes jumping the gap easier.

With the schematic fixed below, you can tell which way a coil is wired. If like yours, you'll have some resistance between the primary and secondary. In the original pic I show , there won't be any.

 

this thread has so many off tangets
never said a plug cannot be fired in both direction. all that was said was that with certain coils and certain applications that issues could arrive.
have you ever torn down a vintage coil?
they are joined common with a brass bar.
there is a reason you see the reverse spark laying outside the chamber with the plugs touching, but hey, forest because of the trees.
the red line is a draw in, not original post and this is a actual coil used in wasted spark or in some apps as a siamese setup. the coil is induction, NOT, center tap or auto coil
you need to study up on current flow, you know, right hand/left hand illustration
so tell me, is it ac or dc????
the scope tells all, no need for the cows to come home, nuff said, end of discussion, people still believe the moon is made from cheese, hummm, swiss or cheddar???
apparently you never worked with vacuum tubes, the ref here was that the electrical energy will transfer better from a hotter surface, don't believe it, find an old vac tube devise and kill the heater.
the point was that the center electrode runs hotter than the shell, firing in reverse loses energy so the need for modern coils which can over come the loss.
the hoodoo single/dual is a no brainer when we are talking about a vintage coil used on the superglide/sportster of the era.

 

The whole purpose of this was to say that the polarity of the primary does not matter. You can verify this by checking to see if the primary is connected to the secondary. If not polarity does not matter. Dual fire coils I have are not connected.

Single fire coils are not auto transformers. Primary voltages do not contribute to the output voltage. They are sort of wired like an auto transformer but spark is reference to the + input. The - end goes to the points.

What vintage are you talking about? The 20s /30s?? You got me there but then a 70s shovel ain't that old.

The main reason why the center electrode runs hot is not electron flow direction. If so Evos and Shovels would be burning up one plug.

Not sure what right hand / left hand means unless you are discussing direction magnetic fields and electron flow. If you are talking about windings, the schematic should have dots to show winding directions. Where is the busbar in your drawings? I suspect you are talking about a single fire coil where the primary is connected to the secondary.

Do know tubes but as I stated, vacuum tubes work in a vacuum which is reason why the cathode is heated. If you don't have heat the metal in the cathode won't emit electrons. Second time I wrote this.

Where did you get that document from?

Everyone knows the moon is made swiss cheese, just look at the surface.

 

Here you go.. An ignition running off of tubes..