There's a sample site of a guy who created a Sticky Header in Notion + Potion. It's pretty ugly but it works.
Here is his code:
https://gist.github.com/normdoow/0f395ce9cfe8a1448252b64c20c994fb
My backup:
https://gist.github.com/bendiscover/4f32cc66b1c4994d9d4e723af383f58d
Backup 2"So you can actually just add your own html and css for the header or foooter. Doesn't have to be in Notion. And you can just put it once in the snippet injeciton. I didn't think of that."
"So just to check (I haven't got Potion yet, I wanted to see if it could do this first) there's a 'snippet injection' section where I paste the code in?"
"yep, thats right."
-Noah, who was on Support chat with me