Hyperlink to the form at the top of the page or open a modal instead

I have a typical lead generation page with the lead generation form in the first fold. The page is quite long and has multiple CTA buttons along the length of the page.

Now I have two options for the on-click actions for CTA near the bottom of the page viz.

  1. Smooth scroll to the top where user can reach the form or
  2. Open the same form in a popup without scrolling.

Is there any study that one is preferred over another for higher conversion?