Re: octave notes
You can then position the two staves above each other, and enable layering for the upper staff, and on Page Setup.
The two staves would then be combined and have the octaves represented.
and will generally look wrong on the printed page.
This technique is useful for quickly finding out how coll'8va or coll'8va bassa will sound. For proper printing, a bit of extra formatting will need to be done.
Edit: corrected 'coll. 8va basso' to: coll'8va bassa