Page limit should not have a minimum of 50

50 is from core I think. You can always just use ?page[limit]=10 if you want less. This is default core behaviour.

https://www.drupal.org/docs/core-modules-and-themes/core-modules/jsonapi... →

Not sure why it doesn't allow less, would need to dive into the why.

The point is to limit it from the server which provides the feed, not from the person making the request. If someone can request 50 and 50 would cause timeouts and pressure on the server then we should be able to stop that by setting a lower maximum.