Do you have users who try to add large files to Change Requests that they should be adding as items instead?
If so, this enhancement could be something of use to you.
This change request asks for an enhancement so that CM Change Request types can have an option(probably in CM Adminconsole) added which limits the size of file attachments, with a warning to the end user if their attachment file size exceeds that number.
Some reasons to avoid large CM CR attachments:
CM Change Request attachments are stored in the database, which takes up way more room than if the files are stored in the Dimensions CM item libraries.
Items have more change management capabilities than CM Change Request attachments.
The cleanup efforts to get rid of large file attachments will most likely be a manual one if you end up having to clean up large attachments to save disk space.