Size limit on accepting data objects

Rather rely on the current activity size limit (2mb), we may do smaller limit like 1mb for a single data object

Start by locating the current 2 MB activity size limit and the handling of a single data object. Confirm how the limit is enforced and whether the intended behavior is a 1 MB maximum for one object; done means the smaller limit is applied and relevant checks or tests pass.

Written by the indexing model from the issue text.