My view is you only submit statements if they have a purpose. And if you do submit one, the statement should be drafted to meet that purpose. This is true at any point in the process. So, if you are considering a statement disagreeing with the MEB, you want it to address factual errors or omissions in including conditions. I would not get nitpicky if there are errors that do not impact the outcome. Your letter will want to stay focused on evidence and not personal opinion. I find it best to state what you want them to do (in a respectful tone), state the standard from the relevant regulation, then cite evidence (which you may want to enclose) showing you meet the standard.
This is more of an art than a science, in my opinion. Others may disagree with my views.