The Dyna-s draws more electrical power than points do from ANY coil used on the bike. This is because of the way the Dyna-s is designed.
With points, each coil is turned on through 190 degrees of crankshaft rotation.
The Dyna-s leaves each coil drawing power through 330 degrees of crankshaft rotation which is an additional 40% increase in power drain from the electrical system, regardless of coil choice.
3 ohm coils draw 4 A while on. 5 ohm coils draw 2.4 A while on. So, 3 ohm coils draw ~40% more electrical power than 5 ohm coils regardless of points or Dyna-s trigger.
None of that extra power draw will make any difference in performance unless you also increase the spark gap at the plugs, (which marginally helps engine efficiency).
The stock 5 ohm coils and points set up draw about 35 watts from the electrical system, and is part of the normal draw of the 120 watts to run the bike and lighting (stock).
A Dyna-S and 3 ohm coils draw nearly 100 watts and increase standard bike electrical load to 185 watts.
The CB550 alternator self limits its output to about 150 Watts (spec'd at 5000 RPM). At idle speed, the alternator makes 40-50 Watts.
The battery will supply the deficit in power draw until it is depleted, by which time you get no spark at all, and the bike becomes street side eye candy.
I'll just note that the stock coils and points were good enough to propel the bike down a 1/4 mile track in 14.02 seconds.
I don't know what or if a Dyna-s would effect that time. But, I am skeptical it would.
Cheers,