Glad to help. Uh-oh... you encouraged me, so now I probably won't shut my trap
A couple other things that helped me out over the past year...
If you really want to go fast soon, pick a simple tune without much embellishment (like Billy in the low ground or Red haired boy basic version). With a simple tune, you can add some decent speed in a short amount of time and it's pretty encouraging.
Once you do the above and realize that you can play some things at a usable BG speed, then slow down. What I mean by that is when I first started doing this, I did exactly like you... I pushed to some speed and then hit a plateau. Let's say 190 for a given song. What I did at that point was keep playing it at 190, often making the same mistakes or playing uncleanly through the same section. What I do different now is I drop the speed to where I reasonably expect to be able to play all sections of the song without error. Do I always play it perfect? Of course not, but in the previous example where I was playing at the speed I had plateaued, I might play it cleanly once in a long while, and even then it probably would not be smooth (legato from your jazz days). A recent real world example for me is "Leaning on the everlasting arms." I learned the notes, and worked out a few harder sections with increased attention, and then started playing it and increasing the speed. I spent a lot of time around 140 bpm while I was getting it committed to muscle memory. At that speed, I can see what I am doing and make sure I am not learning it with something goofy involved. At this point, have the pick strokes down, but there are still a few sections that are not as smooth or I get tripped up on. At this point, I have probably played it reasonably well around 180 to 190, but my current practice speed is 165. A few months ago, I probably would have been at 190 by now and playing 80% ok and the 20% not real well. Anyway, when I get really consistent at 165, I'll bump it up to say 170. I think the song sounds good around 200, so that is my ultimate target, but here's another key... I don't expect my normal practice speed to ever get there (unless my performance target changes to something higher). Other tunes that I play around 200, I generally practice in the 180 to 190 range. Of course from time to time I will play it faster, but that's generally when I am just "playing" and not practicing. My focus in practice shifted from playing faster to playing cleaner. Oddly enough, I think that has been key to break through the speed plateaus I had hit.