Recommended hero image size in gramps-web?

Is there a recommended size or aspect ratio for the new hero image feature? (Great idea.)

Gramps 6.0.8
Gramps Web API 3.13.1
Gramps Web Frontend 26.5.2
Gramps QL 0.4.0
Sifts 1.3.1
locale: en
multi-tree: false
task queue: true
OCR: true
chat: true

The image height is always fixed at 180 px. When choosing this value, I was mostly looking at images with aspect ratio not too far from one, like coats of arms or association logos. A very wide image might end up too large, but it’s easy to solve by adding transparent margins (PNG or AVIF) top and bottom. Gramps Web thumbnails started supporting transparency a couple of versions back.