Official comment
Thanks for your feature request.
Currently ONTRAforms don't allow this capability but our Legacy Smart forms do. If it's an internal form and the two columns are important enough to rebuild it for ease of use, you might consider rebuilding it in that form builder until we make that feature available in ONTRAforms. If you want to place the new Legacy Smart form on an ONTRApage, copy/paste the Javascript code into a custom html block.

We'll keep this feature request open as we do have intentions of upgrading our ONTRAforms but we don't have an ETA just yet.