Those boxes can also be removed by turning on the ‘Enable Legacy Markup’ option under the form’s Settings (at the very bottom).
At least that works for me.
I fear however, that we are not far away from this plugin losing functionality as Gravity Forms continues development and this does not.
I’m researching right now – and thinking of this exact kind of set-up for a multisite waas on WPUltimo – and eyeing CartFlows as a nice addition.
But does it work on Multisite proper(i.e for the sub-sites) or just the master site? E.g. If I wanted the folks that buy a sub-site to be able to build funnels for their site?