Looser enforcement of musical grammar
Please don’t assume the only use case for scoring software is the musician with a completed composition doing nothing more than transcribing their work.
Scoring applications can be great writing tools allowing us to try ideas beyond our ability to audiate and play instruments.
But the creative process works better if you can be formally wrong - eg, five beats in a 4/4 bar. MS is too fussy to allow easy experimentation and discovery.
Guitar Pro is one application that has balanced creative freedom with tools that support correct composition very effectively. I think MS could better support “creative” scoring if if did not rigidly enforce musical grammar all the time.