You can now set your Master sections' scroll effect to Fixed! A fixed section will stay in its position as the rest of your page is scrolled.
A reminder: Regular sections can also be set to the Fixed scroll effect.
Select your Master section, and from the Inspector, under the Scroll section, set it to fixed.
Keep in mind:
You can only have one section (regular or Master) set to fixed position from each side of your page, e.g. one at the top of the page, one on the left etc.
A Master section set to fixed position must be positioned at the same place in all pages it is displayed in.
Let us know your feedback on this feature :)