Is type of plastic important when choosing a container?

Also, would circular container be better than rectangular for water flow, or doesn’t it matter?

You obviously don’t want a container that will deform when you get close to boiling temp as there are some things that need to be cooked up around 190-195F, but aside from that, I doubt there is much to worry about.

I have both round and rectangular containers depending on the volume I need to cook and I can’t say that I’ve noticed any differences in performance based on the shapes.

Thanks heaps.