I'm not a pitcher or a pitching coach.  I'm just  a fan who watches way too much baseball way too intently, so take it for what it's worth.   I'm not sure what was going on in Spring Training between you and Rags, but I think you should have stuck to your guns on the reworked delivery.  What you are working with now, which I assume is similar to the last several years, just isn't getting it done.  IMO, you just have way too much going on in that windup and delivery that doesn't add anything to effectiveness and introduces multple opportunities for things to go wrong:

1.  Tone down the leg kick just a bit.  The leg kick may add a bit of distraction and deception to the batter's eye, but doesn't appear to be doing anything in terms of increasing momentum to the plate.  Most of it is superfluous motion.  it also gets you in a position where you are leaning way back on your back foot and any little thing that's off gets you very unbalanced.
2.  I'm not sure what's going on with exaggerated wrist twisting at the beginning of your delivery.  Maybe it helps get more torque on the curveball, but it seems more exaggerated than I see even from other good curveball pitchers.  Is that possibly a bad habit you have fallen into?  I seems to me that is another place for introcduction of variation in delivery and release point.
3.  You have a great curveball, but you are throwing it way too much.  If you throw enough curveballs, you are eventually going to hang one.  You can get away with that if the hitters is looking for something else, but if he knows the curve is coming, a hanger is going to get hammered.
4.  That brings us to the fastball.  Yours is not great, but even a mediocre fastball, used properly, is still the best pitch in  baseball and it sets up everything else.  Kirk Reuter made a whole career out of throwing nothing but fastballs that were no better than yours.  You have to keep it down and you have to keep it on the corners, especially the outside corner, but a few more of those would set up the curveball and changeup better.
5.  Which brings us back to that thing in Spring Training, whatever it was.  You definitely could use a bit more velocity on the ol' heater.  It sounded like one of the benefits of the longer stride you were trying out was that it would add a bit more velocity to the fastball.  Makes sense.  That upright delivery may add a bit more downward movement to the curve, but it scrubs all the momentum off the delivery and sort of brings everything to a stop right at the moment you should be exploding toward the plate.  The short stride also makes it look like you are about to fall to either side which can't be good for repeating your delivery and maintaining control.

Sincerely,

Dr. B