Maybe I misunderstand your left side panel. I thought it's related to the object (e.g. a specific chart) that is selected but looking at it again it seems to be related to the entire dashboard.
I was not referring to the form values but to the structure of the form - I just thought the different object types (chart, table) don't have static forms behind but dynamic ones. In your case, as far as I can tell, dynamic forms wouldn't make much sense as your form objects are only textboxes, checkboxes and selection boxes - also you don't have too many different objects to configure. Doesn't matter - was just wondering.
But really a great application! I'm working on a similar platform but not open source and with focus on data generation/collection instead of reporting.