I’ve started to use Template columns quite a bit to give myself far more control over how fields are rendered on a Tab. As a result, I find myself switching back and forth between the Data view and the Layout view and it’s really time-consuming.
It would be far better if the Replacements section (see below) of the Template editor:
were embedded within the Layout designed here:
That way, it would be far easier to make and see the results of your changes without tabbing in and out of the different views.