@flopp
Thanks for that, yes I noticed your thread somewhere and I was delighted to see gizmocuz working on your issue. Unfortunately the changes made broke my workaround hack. It just means I need to look for a more conventional solution that does not include modifying cpp files.
What I will do is re-code my mysensor nodes to use other variables such as V_WATTS etc rather than V_VAR1, VAR2 etc.