Don't Auto-Select the Expression Auto-Fill
When you start typing an expression and the Auto Fill pops up it also Auto Selects it so when you just want to press enter to close the expression it actually auto-fills and closes it at the same time. This is rage inducing. (just sayin). Please don't auto select the auto fill.
Dan Gehin commented
YES! It should work like Google: arrow down or use the mouse to make an autocomplete selection. The default should be exactly what is being typed.
or even worse, when you've been working on a lengthy expression, and the autofill gets in your face and you hit escape to dismiss it, only to have the expression window close on you without any of the changes you just made. That's flip the table time