DEFAULT_MAX_OFFSET

Ours. A twentieth of the viewport of travel past the boundary, which is give rather than a bounce.

It was the depth of a squeeze until the effect turned out to be a translation, and the number came through unchanged: six per cent of a viewport is 132 px on a phone, which is a plausible pull either way. That it survived a change of meaning is a reason to distrust it rather than to trust it — nobody has looked at this one on a device since it became a distance.