For AoE2:DE, there are a couple ways to see a lot more of the map.
The first way works while you’re actually playing. You might try this for AoE4 to see if it works; unless you’re saying you already tried this. I’m pretty sure it won’t work for AoE4, though, sadly:
The other way with AoE2:DE is through Capture Age which is used for watching recordings of your games, but I don’t know if it’s available for AoE4 yet?:
AoE2:DE does have the way described in the first link above, actually. Here was a screenshot I took while playing, and I just have a 1080HD size monitor… well, 1920x1200, actually, but that’s only slightly bigger than 1080HD and is not why I’m seeing a ton more of the game here:
