Where to progress from here?

You have some good things going on there- well balanced, quick feet and you are holding a strong edge in some less than perfect conditions.  There is a bit of rear hand waving going on which can (but not always) throw off both balance and timing- getting your hips rotated a bit more forward and keeping that rear arm closer to your field of view could help.  If you are trying to lay out longer carves, a board with a longer radius sidecut really helps.  The difference I can feel between my 9-ish SCR and 11-ish SCR boards is significant.  You could try widening your stance a bit (1-2 cm) which has the effect of stiffening the board and it might be less twitchy on longer turns.  What is your current set up (board, angles...)?

@eleaf "Typical Wizard", funny.  Good stuff man

You’ve got the “wiggle carves” down.  Those are more of a cross-under transition, retraction turn.

I think you’ve got the ankle steering.  Some might say to progress to down-unweighted cross-over turns, but I might hold off on that.

You mention loosing grip with imperfections, which I think points to poor angulation and weight stacking.

I’d suggest working on pure up-unweighted cross-over turns. Leave the ankles out of it. Just shift your weight from edge to edge for engagement.  Do this on green runs so you don’t pick up much speed.  

Once you figure out where your weigh should be, try some J-turns.  Watch Cherry’s video.  Work on your edging (dump the boots) and getting your weight stacked (bend the knees, don’t spill the drinks).

Once you can do those separately, put them together and you’ll be doing up-unweighted, cross-over turns.  Try to get your momentum going across the hill, and do the edge change going across the hill rather than down the hill.

As you progress to steeper terrain, you’ll probably naturally bring your ankles & knees back into it in order to transition quicker… then you can get into more mid-weighted or even down-unweighted turns.

There's some helpful "INTERMEDIATE" stuff in the CASI manual (even some of the same drills that Cherry teaches):

The "clock face" is another oldy-but-a-goody.  Consider just the right side of the clock, the perimeter is your direction/momentum (not the direction of the board).

A total beginner will be starting with more of a side slip, on the outside edge, skidding along until their momentum is going down the fall line, then change edges as the board is pointed downhill (3:00). Beginners don’t use much of the clock face, with their momentum going mostly downhill:

Intermediates aren’t skidding as much, and engage the downhill edge earlier. They will unfortunately ”catch that edge” if their momentum isn’t matching the board direction. Intermediates use more of the clock face:

Advanced carvers will use the whole clock face and change edges as they’re going across the hill, rather than downhill.

Malcom Moore has a great video on the early edge change:

Malcom also has the up-unweighted, cross-over exercise here.  He calls it "Standing up to change edge" at 4:30 (watch on Youtube and it'll take you there):

This illustrates it well, but I don't agree with his ranking of turn exercises.  As I said, I'd suggest that one, then the isolated J-turns: