I have some more info on learning 25/12.
When doing the chord leaps to gain accuracy, make sure that they are at the intended rhythm, i.e. following the arppeggios. Basically count the notes for each chord, and move it in time with them. This would mean counting '1,2,3' for the first chord as there are 3 notes, '1,2,3' for the next chord as it also has 3 notes, then '1,2,3,4,5' for the top chord because it has 5 notes, then '1,2,3' again for the chord after it, then only '1,2' for the final chord before changing to the next bar. This would mean that when you play it as an arppeggio, you are playing it with the exact leaps you played before.
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Another bit of advice is that when you are practicing the leaping chords, leap from the fifth finger if going up and leap from the thumb if going down. Basically, when you lift off and jump to the next chord, instead of lifting off as a chord, push off with the finger closest to the next arppeggio. This will accentuate the 'roll' of the arppeggio and prepare you better for leaping inbetween arppeggios. You can practice this motion by pretending to play a chord on your desk, then roll it to the side and push off with that finger, then level out your hand and strike your desk a bit further away. When leaping to the right, push off of your fifth finger, and when leaping to the left push off of your thumb (as your RH, reverse for your LH obviously). Hopefully you will get what I mean, and it should help with playing the arppeggios smoothly.
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Henrah