This worked for me, get the latest Dosbox-staging (0.81.0 at time of writing) and use that instead of the vanilla dosbox, then in the .conf file set 'aspect' to 'square-pixels' or 'off' under the [render] section.

It appears as though this one was specifically addressed in Dosbox-staging relatively recently (https://github.com/dosbox-staging/dosbox-staging/issues/1578), and it seems to be working quite nicely. Vanilla dosbox (and dosbox-x I believe) doesn't seem to handle it entirely the same way so you can get inconsistencies, meaning the squashed ball thing, but with dosbox-staging you end up with a round ball in all of the games with that setting.

Some of the intros and menus might stretch or look a bit odd but the tables themselves seem to work well.

I've had a similar experience with DOSBox-X 2024.07.01, which not only allows a 1:1 aspect ratio to be set (thus solving the squashed screen/flat pixels issue), but also solves the bug with DOSBox 0.74 that causes the music to slow to a crawl during the high score entry.

GOG needs to update this.