Well that was quick. I tried to install forge on stretch with ELPA, and it fails to load. I don't have the details on hand, but at first it failed because the stretch version of magit was out of date, but even after restarting emacs with the newer magit version, it would still fail with:
Symbol’s value as variable is void: cl-struct-magit-section-tags So I'm not sure this is going to be easy to package after all... a. -- La nature n'a créé ni maîtres ni esclaves Je ne veux ni donner ni recevoir de lois. - Denis Diderot