Let's say I just want to calculate the sum of all orders from this year.
In order to compute the value I need a container in which I have to place a detail row (which can be suppressed) and a footer with a formular.
I would like to just create a formular which is evaluated even without a container which I can use in the header.
Or even better: It could be a diagram type: KPI which asks for a datasource and outputs a single value. Even with DrillDown.
I already can do something similar if I add a pie chart with expression "true" and a white color but nativ support would be better.