You are right; it is awkward as written at the speed that many violinists take. At number
40, I play downward sevenths, starting on the same notes as written, then in the next bar,
downward A7, B7, up B7 twice; next bar, up C7 twice, downward E7, upward F7. These
three bars repeat, then next one: downward F7, downward G7, G7, A7. Next: Same
downward A7, down B7, up B7, up B7, all starting on the same notes as written. It is
almost exactly the same as the written part, and it is so fast and covered that nobody will
know you have faked it. It sounds much, much smoother and more rhythmic this way. It
DOES require memorization, though, because of its speed.

I play section 58 pretty much as written, and it is fine as long as you don’t attempt to close your thumb every time. Just push off and rotate back to the next placement. In the fifth bar of reh. 58, I use a Gb enharmonic for the F#’s, then an Fb for the bottom E natural in the sixth bar. I return the F to # in the next bar, and the G to natural in the subsequent one. Second bar of reh. 59, I set an A# to use instead of the top Bb’s, to make the distance a seventh instead of an octave in the Bb major figures. On the last 3/4 bar before reh. 60, instead of the fourth D of each figure, I use the A#, so that I can keep doing the same pattern. I also have written in the instrument entrances.