There seems to be an implication of playing downstrokes for accented, or "beat" notes, and up strokes for "less strong" ones, in a couple of posts above. It brings to mind an old march cadence that gave a lot of drummers in my high school band (not a bunch of pro's) quite a lot of trouble. It was straight 4 beats per measure:

1 2 3 4, 1 2 3 4, 1 2 3 4, 1 2 3 4

But if a put in an "X" for the accented beat, and "()" for an omitted one, it looked like:

X (2) 3 4, X 2 X 4, X 2 3 X, X 2 X (4).

NO drummer in our little band who "associated" the "strong beat" with one hand or the other was ever able to master this simple rythm (because they had to "change hands" in the 3d and 4th measures?). Those who were able to play the "accents" with either hand had no problem with it. I can see the same, or similar, difficulty at "show band" march speed (140-160 bpm?)if you try to put the "beat" always on the downstroke on a mando.

I've was urged (mainly by a couple of "how to.." books) to learn to alternate strokes, and to accent appropriately "going either way." For melodic playing on the mando, I find that it was well worth the effort to train my puny muscles to do so.

For "chord chops" a.la. bluegrass, it wouldn't appear to make a lot of difference. Although the chords would be arpegiated differently between up and down strokes, the ones you can play on a mando are (in my personal and extremely biased opinion) so "unpretty" that they need to be chopped to a snare drum simulation anyhow.

This is not meant to insist that anyone should learn to "alternate stroke." I'm just curious whether those who play mostly traditional (and particularly Irish/Celtic/mountain trad) do prefer to emphasise one direction for accents; and whether they feel that it aids in getting the "trad rendering" of such tunes.

John