I have been tinkering around with scandi reprofiling and sharpening for quite some time now, including a lot discussion with BF members, with HH quite a bit. There is more to scandi sharpening than most people think, at least in my opinion. I also approach scandi completely different than thin v bevel knives. First, I use both hands alternating, meaning for the left side of the blade I use my right hand holding the angle and my left hand does the sharpening/moving/pressure. Vice versa for the right side of the blade. This gives me a much, much more uniform grind. I almost exclusively now use the Norton Crystolon stone with oil, I switch to JWS if I reach for a near mirror polish. HH washboard is perfect (with 2 sheats of paper) for refining/burnishing the edge/apex.
I now do forth and back motions, following the belly of the knife, means turning and lifting. That also has the advantage that you can see better when you are at the tip since for the most part, as soon as the final belly part/tip apex is perpendicular to the stone (my stone is 90 degree angle towards me), you are done turning the knife (unless you want to reprofile the tip). Since I actually prefer the very slight convex bevel that you get if you freehand sharpen a scandi (there is almost no way to keep a scandi bevel completely flat freehand plus, the slight convex performs better in pushcut into wood, wood shavings and feather sticks IMHO). I hold the knife quite tight in my hand which contribute to the convexity since my wrist rolls a bit (forward stroke lowers the angle, backward stroke increases it) and therefore the knife has to follow. If you want a more flat scandi, holding it loose and control the pressure with the other hand keeps the bevel flatter on the stone IMO. You can then control the bevel more by pressure points then angle holding!
Once I have established an even grind and burr of course on both sides, I cont. the same motions (for and back) but very very light until no significant burr. On scandi, if I only did edge leading strokes to remove the burr (which I do exclusively on v bevel knives though), you very likely end up with a slight micro bevel on top of the "scandi-vex". It can be done but requires particular patience

The cont. of very light forth and back strokes ensures that I keep my "convex" motion. Now, don't get me wrong, I am talking about a very slight convex if you hold a straight rule against the scandi bevel, you can see it. As HH often mentioned, I guess about a degree or two!
Once the burr is gone and you are finished with your final stone, use a HH washboard (or a strop) for final finishing. I noticed a tremendous improvement of the apex with plain paper on the washboard, if you don't do too many strokes (edge trailing this time of course). I have also not noticed any rounding of the apex!
Sorry, this was a long rambling!