Broadforking on contour: fork parallel or perpendicular to contour?

My basic question is if one wanted to get something closer to keyline benefits from broadforking on contour when on slope, how would you orient the Broadfork and plot your course? Would you face uphill/downhill and work along the contour sideways? Or, alternatively, would you work somewhat awkwardly (potentially dangerously?) with the Broadfork going as close to straight in as possible with the tines going along on contour while moving forwards/backwards. As I write this I think the former seems safer and more ergonomically sound. It seems that the fork loosens a cavity parallel to the cross bar of the fork, which if only contour or slightly sloped towards the ridge would conduct water from wet to dry points and aid infiltration/aeration.

I am pretty new to broadforking (it was a gift) and have only seen videos on its use on relatively flat Eliot Coleman style beds, which I have used it on (ie asparagus beds). It seems to me though that my rocky clay with little growing on it due to exposure, erosion, and a surface hard pan (in places) could benefit from keyline ripping, and/or a broadforking. Why not try to get the benefits of both in one fossil fuel free pass? Literally, I am interested in your feedback.

I have a mostly sloped property where I am starting a food forest with fruit, nut and n-fixators planted mostly planted on contour (where feasible without blasting out bedrock). I have drip line, also as close to contour as feasible, for irrigating the 80 or so trees in my zone 1-2 fenced area. I have another 400+ trees in zones 3-4, where I did not hold to contour nearly as much. In zone 3 about 110 of the trees are caged. Almost all of it is on slope from 3%-20%. I have mulched everything in zones 1-3 with woody debris and duff inoculated with compost and top dressed with kelp and rock dust. Again, I think anywhere i could keyline and/or Broadfork would benefit it and am interested in anyone’s thoughts on trying to get the best of both with as little work/energy usage as possible.

How about an experiment?  Divide the contoured area of interest into two sections, and try both and let us know!

1) On one day, try the uphill facing, lateral side step method.  
2) On another day after resting up, try the uneven forward-backward slant slope standing on contour method.

Measurements for each:

 A) How many feet or meters can you cover at an easy pace after 10/30/60 minutes?
 B) How sore are you after 10/30/60 minutes?  Which muscles?
 C) How does the micropattern on the ground look?  Maybe take photos, too?

My hypothesis is that method 1 will start out really comfortable and feel very effective, but it will slow down and become more tiresome in the end, whereas method 2 will start out awkwardly, but in the end will be faster and more comfortable.  

I think with method 1, the motion will feel like stepping up and down stairs many times, and then lifting a box from left to right (or right-left).  I think you'll find yourself lifting the broadfork up and down way more relative to your body, too, because you'll tend to step far downslope.  All that up and down stepping and lifting and lateral motion will add up.

With method 2, I think it will be much easier as you "drag" the fork out of the ground speedily and slide it aft, stepping backwards along contour.   I bet your body's center of gravity will change less than with method 1, so you'll feel less tired at the end because you'll be doing less work overall.  Your body's push-pull forward-backward muscles I expect are more well developed than lateral side stepping.  Additionally, I bet the 20% slope won't feel very big at all.  With say, 15" shoulder width, that would be a difference of only 3" between left and right feet.

Let us know, though.  I've considered doing this myself!

I would say you want to watch what happens when you have the fork in the ground and pull back. I would guess that you'll create a crack in the soil along the line of the tines. That would mean that any water flowing downhill will seep into the crack catching any soil washing with the water.
My guess: the biggest benefit will be if the fork is parallel to the contour line.

Any update on this? I'm doing perpendicular to slope but I have like 2-3% grade. We have very sandy soil but I haven't seen too many problems with erosion or anything washing out. In fact these beds seem to be holding nutrients better than my no dig.