Currently on Blorp, when scrolling through the comments of a post, there is a top bar with the community and post title/thumbnail, and a bottom bar to comment on the post.
My suggestion would be to have an option to hide both bars when scrolling down and showing them when scrolling up to maximize screen space when reading the comments, the top bar could also only be hidden partially, leaving either the very top of the bar, or only leaving the post at the top while scrolling.