Found a solution by CSS the hell out of it! =)
Since the form is structured as an Unordered List, css3 has a command called column-count: x; (x is the number of columns you want). I applied column-count to a new css rule for the form's UL, made the form relative to the parent div, and then took the last LI which is the submit button and made this absolute. This way i can move it across the full length of the 2 columns.
column-count works only on modern browser IE10+, chrome 50+, firefox 2.
If there is another way i would love to hear about it.
Maybe a future version of Machform will have the ability to split a form or a vertical separator?
Thanks.