Really curious if Andy Bonner or Tetsujin have opinions on this^^
I never had a teacher and never really followed a method. I suppose my "method" is to just visualize an E minor pentatonic scale across the whole instrument -- using my knowledge of the geography on a guitar and a few landmarks on the bass. Then I just mentally find the half steps in the middle and trying to find comfortable fingering to get the notes I want. Rather haphazard an unmethodical really.
I have a copy of Simandl vol.1 but never really cracked it open. But maybe this new one would be useful if I'd actually use it.
@gadfly I would say your best bet is to go ahead and start learning it and see what difficulties you run into. There is some quick finger-work, but you'll have encountered things like it in the pieces you've already played. There's a bunch of playing in octaves — both as chords and broken — but practicing the piece itself is as good as any exercise you'd find. Mostly it's just longer than other things you've played, but also very repetitive.
@gadfly I encourage you to give it a shot once you've worked your way through the other things you want to play.