Your motion allows essentially that every member of Parliament would have an opportunity to speak in the House on any proposed changes to the Standing Orders and that there could be no limit to that debate. It could be as protracted as it needs to be, potentially.
How do you ensure that a majority government couldn't whip a vote? Essentially, I think you're ensuring that the vote might be procedurally free, but it wouldn't necessarily be politically free. In the case of a majority government, at any point in the future they could propose changes to the Standing Orders. If it comes to a vote, obviously they could whip that vote.