Despite what is said on sohc4.net, it is easy and effective to get good ignition on your CB500/550. First, if you don't suspect the ignition coils (which are easily tested, but not the manual's way) then just sharpen up the lower side of the system, the points. Use factory TEC points assemblies, and a factory plate, and condensors. Service the advancer assembly by inspecting it and lubing it lightly. And carefully time the system--this is 80 percent of tuning. That is, the ignition setup and timing is more important than carb work and adjustment, valve adjustment, all of that. It is a major part of tuning the engine. Be sure to check timing both at idle and at 2500 rpm, which of course requires a strobe-type timing light.

If you want to take it to the next level, I heartily recommend the Dyna 2.2 Ohm ignition coils, the gray ones, which are the ones I run and have installed on customer's bikes. Do not use Dyna wires, instead make your own out of raw materials--the parts are available all over. Solder both ends of each spark plug wire, and gap the plugs to 0.030". If you want to keep the resistor caps you can, but unless you are running a radio or other sensitive electronic gizmo on your bike, there is no reason to do that. Make the wires extra-long for the benefit of graceful arcs and so that you have plenty to incremently nip off every few services. On the lower side, double-springing the points can make a difference, but not that much unless you are riding a lot at extreme rpm. I did this for decades on customer's bikes but never on my own.

There is no good reason to fit the Dyna module (trigger assembly). All arguments disappear like a vapor once a knowledgeable person is in the discussion, because the Dyna is just as much work to set up as the stock system, so the only benefit is presumably longer life. All the aftermarket ignition module systems fail at some point too, something that will never happen with points. And of course you already understand that the Dyna S promises no performance advantage.

Don't forget to get after all the wiring harness connectors, which are the source of poor voltage to the ignition coils. This is preferred over the relay mod which is just "Band-Aid-ing" the situation and not really fixing anything. Don't be a 'net lab rat.