Guest Russ, I agree with all that you have said which renforces what I believe, jigs just aren't taught in most banjo tutorals. I learned form Eric Muller & Barbara Koehler's book "Frailing the Five String Banjo" there is not a single jig there. But in the old days (minstrel banjo days) Jigs were quite common. Check out "Ryan's Mammoth Collection 1050 reels & Jigs" (fiddle tunes) printed originaly about 1880 & it is chock full of jigs.
Muller & Koehler's book does have a few numbers with triplets & these are the foundation for doing double jigs. to get the 6/8 time I count as follows
"One", "&", "a", "Two", "&", "a", "One", "&", "a", "Two", "&", "a", etc. I emphasize the "one", "two" beats with the downward plucking of my index finger. On the "&" I get these either by drop thumb, pull off slide, or hammer-on. The "a" beat is done with the plucking of my index finger also, but not as strong as the "one" or "two" beats.
So what you have here is two index finger pluckings next to each other.
put another way Count "One" (index finger); count "&" ( drop thumb); count "a" (index finger); Count "two" (index finger); count "&" (drop thumb); count "a" (index finger) repeat
I set my metronome for about 100 BPM at my playing speed. This is a little slower than the likes of Altan. But I think is more of a danceable speed for the common folks.
I do hope this helps, Charcloth