I've just tried Abstraction as Boundary Point with a Time serie instead of considering the Irrigation Tab (in this case a specific catchment definition is required). In my case I'm analyzing a very complex sistem where my interes is focused on mean fluxes. Measurements show me a seasonal discrepancy with model results after autocalibration and optimization.
Using the time serie abstraction in local points, you can check the irrigation abstraction and ET consumption and it works quite well.
I'm working with that for the moment....