I have been a subscriber to VPP for a few months but only in the last few weeks have I been getting regular hits on the battery, both morning and night. My observation is the discharge to VPP has been from 1-2kWh (up to15% of capacity). This is all within the guidelines I have agreed to.
The downside for me is 2 days a week I use 80% PowerWall 2 battery capacity to recharge my Mitsubishi PHEV 2021 for office based work travel, leaving 20% capacity to run my house overnight. Without VPP this is not a problem.
If VPP discharges my PowerWall 2 battery in the evening on the two days I need to charge overnight, I am forced to run my house on Off-peak grid power.
I would like to see an ability to 'quarantine periods' when the VPP discharge can be blocked from hitting my battery for predictable household/EV requirements.