Hi!
I was in the same situation. A local jump school wanted me to fly for them, and I told them I wouldn't until I got my add-on to me Comm or ATP (one was Helo, the other AMEL). They said a lot of guys did it-but I thought about what I would say during an interview.
While I was working on it, I got called by an airline for class, so I stopped training for it and still haven't got it. I think I'll do the add-on to my ATP, at some point, as that'll be easier than the add-on to my commercial.
Cliff
GRB