Restrict pitch input to defined range
My usual method of entering notation is to touch type from a pc keyboard. MS attempts to guess which octave a note should lie in as I enter it. It gets it right more often than not, but gets it wrong sufficiently often to irritate, particularly when entering things like Alberti basses. Try entering the attached example. CTRL UP and CRTL DOWN are probably my most often used keys when using MS.
In the absence of a mind reading facility one possible method to improve the hit rate would be to (temporarily) restrict the pitch of entered notes to a defined interval. A note that MS would currently automatically enter outside the defined interval would be entered an octave higher or lower to bring it within the defined interval Anything that you really want outside the defined interval could be put there as now with CTRL UP/DOWN. To aid the entry of the attached example, the range could be set to F3 to E4. This would only leave the high G4 in bar 4 to tidy up, rather than having to adjust every D that follows a G and G that follows a D etc.
As regards GUI implementation, I suggest an addition to the tool menu "Restrict note input range" with a dialogue box to enter upper and lower pitch limits and a button or tick box to activate/deactivate. This would affect note entry on all staves, but I only enter notes on one stave at a time. Alternatively there could be a set of buttons or tick boxes to select which stave or staves the limit applies to, or possibly an option to set the range for each individual stave. These seem a bit of overcomplication, but others' methods of working may make it worthwile.