So I am an airline dispatcher in real life, and have flight and jumpseat experience. I could make a mile-long list of changes.
But one issue stands out most: dealing with ATC. The first thing my flight instructor taught me was to aviate, navigate, and then communicate.
There are so many things to do, especially in solo pilot operations, which are definitely not allowed in the Part 121 world, but I digress.
It would be nice to have a “standby” response to give us time to adjust the aircraft or handle anything. A 90-second timeframe, then ATC could contact us again. I don’t know; I’m not a programmer.
And also there is no verifying contact after you make your inital call to a new center.