Hi CC forum!
I’ve been working a lot lately on the cascades of 5 and 3 and get a natural feel of the down-down pick when going down a string. On my Strat it feels pretty smooth, despite the fact that rhythmically it’s still a bit hard to get the down down emotion to be just as tight as my normal alternate picking. I tend to do a little mute on the strings to be able to achieve the tilted pick slanting position. The other day I tried to practice these things on my jazz box because I also want to incorporate it in a clean-tone Benson-ish vibe. But here I faced a technical issue when using jazz box and not my Strat. My right hand doesn’t feel familiar anymore, and it’s hard to achieve natural and relaxed position. My jazz box is a peerless New York 17" which is a huge guitar compared to a Strat, and I’m not a big guy 
Have some of you faced identical issues or have any tips? I’m also considering whether it would be easier on a smaller jazz-box or a more electric jazz-box, lets say a es-175 or Ibanez pm (not that this is only the guitars fault) Hope it makes sense, and maybe you have some tips for me? Best Regards Mathias
Just keep going for it on the Jazz box - your hands will eventually adjust to both. I had a similar experience and the difference disappeared as I started consciously choosing a variety of my guitars to play on. It does take a little time.