Unsurprising to admit, but I prefer to rake. The main reason for this is tone. But the other reason is that SA picking is uncomfortable. This is hard to explain: we are talking about free stroke plucking as opposed to rest strokes, correct? in order to do that, I find my hand curves more, pushing my hand further away along with my thumb, which i anchor. This makes muting exceptionally difficult and bends the wrist more. This is not as comfortable as how I play using raking.
I am talking about rest strokes. This is coming from a place to the side of bass guitar, but I learned classical guitar before and during and cross over some of the techniques. Your problem reminds me of issues I had playing descending scales. The solution was to practice right hand alternating.
If I was playing a pattern that ended with the index plucking the G string and moved to the D string, I pluck it with the middle finger.
1) The index finger plucks the G string and rests against the D string. When I pluck the string it is with the tip of my finger near the nail. My plucking motion is a combination of pushing down as much as it is pulling the string. When it rests it rests halfway along the pad in a different place than where I pluck from.
2) As my index finger goes into the resting position, my middle finger gets in position to pluck similar to the the index finger in step 1.
3) The middle finger plucks as the index finger relaxes off the string. I don't think I pull it away. I just stop flexing to pluck and it relaxes off the string so the middle finger can pluck.
The problem with raking quickly becomes the fact that where the rest strokes lands on the next string it is not in the normal plucking position so the hand tightens to get through it.
The solution would have to either be to adjust where the rest strokes lands on the next string so that it is ready to pluck or to alternate fingers. I think that ramps and playing over the pickup are trying to achieve the first. The problem I have with it at this point is that plucking across like that instead of downward loses some of the apoyando tone.
Alternating does feel awkward when you first try it. I wish I could go back to when I raked and film me playing scales before and after switching to alternating. I could play fluidly ascending, but descending would sound like a pause everyone I switched strings. After a month, it was gone. Before that no matter how hard I tried, I couldn't get fluid speed up and down.
A lot of guitar exercises exist for it, but the main one I started doing was practicing the Segovia scales.
It was just an idea anyway. Thanks for humoring me.