I have a view that represents a dashboard, in it I include several panels with dynamically calculable data, to display each panel I use the render(controller(...)) method. Is it advisable to do it this way, or calculate all the data in the view controller?
Although it could be interpreted as an opinion-based answer, the fact is that the official symfony manual itself advises its use.
what does it mean
That being said, it is completely logical and widely used to create methods in controllers to generate pieces of code when they are going to be used in various places in your application.
But if, on the contrary, you are only going to show them in the "dashboard" of your application, perhaps it is easier to load all the values in from the controller, and organize each block in templates making use of it through blocks of type
include