If I have 3a curls...

[BigFatMoonHead]

How much styling and tweaking would this haircut take each morning? Would it even work?

I desperately want a pixie cut but struggling to find what will work with my hair and my very round fat face!

IMO that cut would take work every day. Your curls would flatten and frizzy quite a lot overnight. It's too short to tie up overnight but sleeping in a silk scarf might help.
I wear my hair curly and straight and I think curly requires more effort to look good.

That's very close to my hair a couple of years ago. I did virtually nothing to it - washed it each morning and put a little bit of styling wax through it. It was pretty much dry by the time I got to work.

I do struggle with frizz but my curls can usually be revived with some cold water and some scrunching. But shorter might be less forgiving?

Right now all I do is plop it while I get dressed, blast it with cold air + diffuser for a couple of minutes and then leave it to air dry. Because it's long it takes a long time to air dry although I don't have to fuss with it any more than that.
I would hate to be proper styling it every morning.