That's great. THanks for your help here. Think I'll leave it in there to create the initial configuration file so it creates one that I can copy and amend to variations of the config, then re-deploy the package with that file removed.

I must admit, it does seem a crazy change by Microsoft this as it's designed to assist with dev v production environments ok, but has a horrible detrimental affect to packages that need to be run differently in the same environment, like in my instance. Yuk!