The Model T magneto is just
8 16 horseshoe magnets and 16 coils, its output is pulsating (ripple) not sinusoidal but a peaky triangle waveform. There are dead spots at certain crank angles where the magneto instantaneous output is too low to generate a spark, so there could be a delayed/retarded spark always happening if the Timer was ahead of a magnet.
If the magneto was at a zero cross, there will be no spark possible even though the Timer is commanding a spark to start. Ford was on top of this, the magnet positions were synchronized on the crankshaft and advanced 7 degrees. But still deadspots exist. There's also like 10 revisions to the magneto design.
I don't think spark intensity is as much of an issue (beyond cranking) as is timing accuracy.
I noticed somebody went full tech and made a
Model T replacement Timer with microcontroller, Hall sensors, IGBT's. It looks good, would people here put one in or use the original buzz coils and timer?
Given you can break your arm if the engine starts up in reverse, and nobody likes to hand crank an engine much...
edit: it's patented
US 8662058 which gives all the electronics details.