This response is provided based on the information you shared and should not be used as the sole source for making a decision. You should seek guidance from the chain of command, IG, JAG or other certified agencies before making any decisions. How you chose to use this information is totally up to you and is your sole responsibility.
I am not sure what you mean by leniency. You can most certainly write the commander but I am unsure as to what you would say.
You can also call and request to speak with the First Sergeant and/or Commander. They don’t have to speak with you but they may out of courtesy.
Remember they consider your son an adult free and clear of parental rights and therefore must make their decision solely based on the facts surrounding the issue, but may if they desire take into account information you wish to share.
Does your child know you intend to communicate with the chain of command? It would be wise to let them know and seek their approval to do so.Hope this helps to some degree.