Managed to get out for a solid ride on the weekend with the collection bottle. Initially no visible coolant collected in the bottle while relatively 'normal' riding. The area I wanted to try and replicate the the type riding I was doing where the last 2 water pump failures occurred is mid way into this 370 odd km loop and is a series of tighter corners where you can use a lot of on/off 1st gear continuously for about 16km (it's actually called 10 mile corners). After this section, and a lot of corner exit wheelies + TC intervention I pulled over to see approx 15mL of coolant in the bottle. It seemed that after this no matter how I was riding, the coolant kept weeping from the pump. By the time I got home there was approx 50mL of coolant in the bottle.
Drained it, took the bike for a local cruise to get breakfast the next day and once again, zero coolant in the bottle.
From this test, on my bike anyway, it seems that I can reasonably conclude that this particular water pump needs heat and high RPM 1st gear usage to start the weep process off. Once it starts it doesn't seem to stop until it's cooled down again. My first failed pump happened under the same conditions but didn't stop and got bad fast.
Hopefully this is enough of a test for Ducati to replace the pump.