Is there an easy way to remove a custom form from a Project?
There doesn't seem to be a MISC action to do this. The only way I can find to do this is to do a PUT on the PROJ object and basically pass in the existing objectCategories collection (minus) the object ID of the custom form that I want to remove.
Are you using a Template to create the project? Could you remove it at the Template level? Fusion will add the custom form if you add/map to the custom field on the template and auto-add the form so I think my suggestion might work for you.