I like to do multi-line formulas and use indentation as well.
To insert a newline you have to press [Alt]+[Enter]. To indent you can’t use [Tab], so you have to manually space it out.
My script swaps the [Enter] key behavior so regular pressing inserts the newline and Alt+Enter commits the formula. It also converts a Tab press to 4 spaces (rather than focusing away from the bar)
I just have my formula bar set at 3 lines and F2 edits in the formula box always. I find that works well for me.
What frustrations do you have with the default setup?