The max (power used – power generated (=PV)) is relevant for the connection that you need e.g. 3x16A, 3x25A, 3x35A, 3x50A, 3x63A, 3x 80A, etc (17kW, 24kW, 34kW, 43kW, 54kW, etc).
In the Netherlands (and elsewhere?) you pay extra for a bigger grid connection.
If you add a PV system the max net power usage decreases and sometimes a smaller grid connection is possible. It is useful to know for a longer period what the net peak power usage is.
So please add max (power used – power generated) per lifetime, year, etc to the statistics page.