I still can't decide which I want to play but it says they work together... so I was thinking of giving it a go.

However, from SE's description...
Map gen settings: It is advised to reduce the resource richness and size in map gen below 100% or you will still have more resources than you need. Reducing enemy evolution rates is also a good idea.

I'm not really sure how this all works with Krastorio, since it has more expensive recipes in the early game. How balanced is everything and what should my map settings look like?

Has anyone tried?

We did a big work so that the Krastorio will be compatible with SE.
I think that if you leave the resources by default, everything will be fine.