how to export PRJ file without BreakPoints?

Here's a snippet from my Studio Extension (a subclass of one of the more standard extensions) that you might use and adapt in yours. It deals with a few other things that /diffexport misses - the timestamp, and the order of project items (which will normally have newly-added items at the bottom, out of alphabetical order). Unfortunately, I haven't found a way to handle breakpoints - probably the easiest way to get rid of those would be applying an XSLT to the file after it's been exported, which is pretty bad.

Method OnAfterSave(InternalName As %String, Object As %RegisteredObject) As %Status
{
    Set tFileName = ..ExternalName(InternalName)
    If tFileName = "" {
        Quit $$$OK
    }
    
    Set tName = $Piece(InternalName,".",1,*-1)
    Set tExt = $ZConvert($Piece(InternalName,".",*),"U")
    
    // Special handling for projects to ensure that newly-added items don't show up at the bottom of the XML export.
    // This tends to cause meaningless diffs (at best) and conflicts (at worst)
    If (tExt = "PRJ") {
        Set tProject = ##class(%Studio.Project).%OpenId(tName,,.tSC)
        If $IsObject(tProject) {
            // Save the project for real (we'll be in %OnAfterSave for the project when this happens,
            // but %Studio.SourceControl.Interface protects against <FRAMESTACK> by moving %SourceControl
            // to tmp, so this should be perfectly fine).
            // If the project is not saved, the items will be in the wrong order.
            If tProject.%Save() {
                // Reload the project. We need to save first to be sure all ProjectItem changes are commited.
                // This will load them up freshly, in the normal order.
                Do tProject.%Reload()
            }
            // Clear a few properties, since /diffexport won't be respected.
            // This won't actually be saved, but these things shouldn't be in the export to disk.
            Set tProject.LastModified = ""
            Set tProject.Target = ""
            Set tProject.TargetType = ""
        }
    }
    Quit ##super(.InternalName,.Object)
}