My third monitor is 1,080 × 1,920. When I was rolling with my home-grown character sheet it used all that height. The D&D Beyond character sheet not so much. I made a bookmarklet to address the two parts of the page that have the annoying scroll:
D&D Beyond Character Sheet for Tall Monitors
D&D Beyond recently added a dark mode. The original bookmarklet had to set a background color to work, but that conflicts with the dark theme. The following bookmarklet accounts for that and also makes the overall page background darker.
D&D Beyond Dark Theme Character Sheet for Tall Monitors
Drag that link to your bookmarks bar for real awesome fun. I have no idea if it works on my sample character sheet when not logged in.
Before:
After:
