When editing forms for data collection, either in Map Viewer or Field Maps designer, I think the "Logic" section is quite confusing for new users. See the screenshot below.
I don't think "Calculated expression" should be in the same "group" as the logic elements. It is indented in, along with Editable, Required, and Visible, making it look like these items do similar things.
When I started, I wanted to create a calculated field that I could then have users edit. So I messed around with trying out expressions under both the "Editable" section and the "Calculated expression". It took me a long time to realize that the first three options just control whether the field is Editable, whether it is required, or whether it is visible.
It's also not clear that if you calculate an expression, it's not Editable. Survey123 allows you to do this and I assumed Field Maps forms would allow same.
The "Calculated expression" section should be in a separate group with a header the same style as "Logic", in my opinion.