This has been addressed in the wiki:
http://wiki.contribs.org/Advanced_SambaServerRole functionality is now part of the core SME packages, but are "post-SME7.4" so they've not been released yet, but can be installed from the smeupdates-testing repo. I personally run these packages on all of my production machines and have talked with others who are as well.
Yes, the current smeserver-adv-samba package works on SME 7.4 and the current SME 8 beta.
I'm confident that you can upgrade the forked packages with the ones in smeupdates-testing cleanly. Make sure you do a signal-event post-upgrade;signal-event reboot after you update these packages.
If you have any trouble, be sure to let me know.
Greg