So, it seems like the only thing to do now is to put some hours/days/weeks of work into this, right?
Is there any strategy on how to approach the practice the best?
Training proper movements at slower tempo?
Just forcing myself to try and play the thing at 100% hoping it will finally click?
To give some insight - whenever I had to play anything with fast tremolo I would put my hand in pronated position, get all tense and just bash the strings as fast as I can. But this way does not give nearly enough control to switch strings or stay true to the metronome.
Now I try to use suppination, and that is a partial success - I have much more control and can relax a bit, but I am still yet to discover the proper picking mechanics, like how to make each stroke even and pronounced. I tried to have the pick at an angle, using the edge, and while it makes it easier to pick strings fast, it also sounds mushy.
And also I realised that it is not the speed that I need to improve - my hand is perfectly capable of reaching the desired tempo, I need more control over it - to make it even, in time, and to be able to switch strings freely. Also, I need this to be more reliable - one day I am struggling to pick at 120 at all, and one day 180 seems suspiciously easy!
EDIT: one more thing. It seems slighly more douable with small, thick and pointy pick, BUT it constantly slips out of my fingers, I rub my index against higher strings and it is difficult to switch to lower strings.
Maybe I am overanalysing it, who knows, but that’s what I noticed.