I would use a Guided! I was just saying, if a freeform already exists and needed to be tweaked instead of being replaced, there are desperate measures you can take.
There is no such thing as “Mobile Compatible” for a Guided template, as the look-and-feel of the page is entirely driven by the template. So, if you are using a responsive template that adapts to different screen sizes (like our example templates do https://docs.marketo.com/display/DOCS/GuidedLandingPage+Templates), then your page will already look good on mobile. The “auto create a mobile version of the page” feature only works with Free-form templates.