RE: How to remove the integrated roll
You could take your new North sail to a sail loft, and they can cut the integrated pulley off the tack of the sail and add a pressed in grommet
(like what your are accustomed to) but where will they put it?
The integrated pulley "system" is made to pull down your sail at the correct angle to load the lower panels correctly.
As far as the time it takes to thread 3 sheaves in your downhaul tackle, it shouldn't be anything more than about 30 seconds.
As to your friend having to put the extension in the bottom of the sail so he doesn't have to rethread the downhaul line, that's probably why it takes him so long to rig.
Leaving the extension attached to the sail so he does not have to rethread the downhaul is almost funny....
Can't be good for the sail, must make it a bitch to roll up and un roll, and it can't be good for the downhaul line.
I think you are going to have more problems deciding what mast base system (rollers across or rollers fore and aft) to use with your North Natural than you are going to have any problems with an integrated tack pulley.
Hope this helps,