Larger plug gaps - with a stronger coil and a resulting larger spark probably were needed to fire a wide range of fuel mixtures resulting from chokes or other enriching systems used for cold engines - did these engines rev up when started?

With proper mixture and ignition computers and better designed combustion chambers perhaps a smaller spark is plenty.

All the bricks that I have owned ran fine, and their plugs looked great when tune-up time came.

BTW I do not think that you can blow a spark out - higher levels of fuel and air in the cylinders may have made the smaller spark adequate.

The above is just my thoughts on the topic - I would love to read anyone's else's thoughts.
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'96 855R,'64 PV544 driver, '67 P1800 basket case, '12 XC70, the first three are mine, heh, heh, 525,000 miles put on 10 bricks