Is there an easy way to select all the lowest notes in this arpeggiated line?
I’m not sure if I understand you correctly, do you want to select all the orange notes in the screenshot or only every second note?
In the first case you do select everything, rightclick>Filter>Select Only>Notes in Chords>Bottom Notes. Or you invoke the jump bar with “j” and type “bottom notes”.
In the second case it depends on what you want to do with them.
If you want to manipulate them, the easiest way would be to use the rectangle selection bar by bar and try to catch only the bottom notes. If you want to paste them somewhere else, copy all the orange notes, paste them somewhere and press quarter note and then eight note (without insert mode turned on), that way you only have every second note.
Best regards
Stephan
Thanks.