Dart Thrower switching unconsciously to Reverse Dart Thrower when trying to do fast downpicking

Technique Critique
#1

Hey! I intend to ask this also in TC but I’m eager to get some feedback before I officially ‘unlock’ the option.
So, recently I’ve been experimenting with a new motion that (I think) is the Dart Thrower. I can do fairly quick alternate bursts and sustain a tremolo for a good 4-8 bars at a decent tempo. However, when I try only downpicking I’m very slow and if I force it I unconsciously switch to Reverse Dart Thrower!
My question is - do you think it’s just the old habit kicking in and the new motion needs time to settle. Or does this motion have some kind of limitation that forces me to seek other motions when I push for speed?

#2

I’m not saying there isn’t a wrist component, but the motion seems to mostly come from the forearm. You can very clearly see it twitch when alternate picking. Then the movement goes away when you start downpicking.

This is pretty similar to what I do as well.