I’ve definitely hit that same wall before. Chromatic drills are good, but what really helped me was mixing in musical patterns instead of just straight exercises — like using scales in thirds or arpeggios with string skipping. It feels more “musical” and trains the brain as much as the fingers.

For speed, I’d say focus on relaxation first — if your shoulders or wrist tighten up, you’ll burn out fast. Practicing slowly with a metronome and only pushing the tempo once everything feels effortless made a huge difference for me.

Have you tried incorporating small bursts of speed practice (like 5–10 seconds max) rather than long runs? That approach kept me from getting fatigued while still building up control.