Addendum for softs? Forum

[HopeyDopey]

This is basically part 2 of an earlier question. In undergrad, I founded and was president of two student orgs during my senior year. Unfortunately, I way over extended myself and I wasn't able to devote much time to these orgs. I was involved in an internship. Long story. I've been told that I probably shouldn't even list that I was involved in them, but I have letters of recommendation from professors which have almost certainly mentioned that I was a part of these orgs.

-Will it look bad if I don't mention them if my LORs do?
-Should I consider submitting an addenda explaining why I did not have much time to give on these orgs?