Should stop trying new toys to play with. Managed to flatten all 5 batteries here trying to export to the grid.

Set the system here to export at timed intervals. These intervals certainly worked. Which is good in itself. Thank you Simon S for adding the settings. (was hoping to find a way to export to no more than 40% of charge available over both export periods but couldn't find a way to do this. Would be very useful if this ability could be added later. That would save me flattening the batteris.....)

Need to wait a few days to re-charge, me thinks.