WITH_ITEM() best practice / trick?

I have a single input form with bindings like:
So data[0] goes to that “hold” page var list of objects allFormData.services.
When I click ‘add more’ button, I set the page var with the formula below so that the form is ready for new indexed input [1], and [2] and so on as I hit add more.
WITH_ITEM(pageVars.allFormData.services, {name: pageVars.allFormData.services[pageVars.index].name, title: pageVars.allFormData.services[pageVars.index].title})

But my pageVars has twice the data. The two-way binding makes it that pageVars already has all the data from the live input, and the items in WITH_ITEM(list, item) makes it that it adds the data a second time.
Got any trick folks?