I did a 356 W rebore/rechamber in a Marlin 336 which is basically a necked up 307 case and I didn't have any problems with using 358 cases or reformed ANY 0.473 based case as far as shooting or ejecting was concerned and I didn't do anything to the 336's ejector or extractor...I tried 307, 308, 30-06, 8mm, 7mm necked up to 358 cal, resized and trimmed, loaded with the same charge and bullet and mixed in the mag tube rimmed AND rimless, grabbed out of a pile of loaded ammo and stuffed in the loading port...nary a hiccup. There was a gigantic freakout over the whole situation...but I don't think anyone except a few even tried to see if what I said was true or not...I use 308 cases because they feed better.
What you are doing is basically the same thing...giving you the ability to use a rimmed and a rimless case...the 307/356 cases are slightly harder to find and seem to be run seasonally. When I was doing my conversion 307 cases were non-existant but the 356 cases were available at Cabelas...last time I looked both were available through Midway, Cabelas, Lock-stock and barrel, Midsouth and Natchez.
I wouldn't try to talk you out of doing it as it is an interesting project.
You can load it to standard 52KCUP pressures just like any of the '08 or '06 based calibers in the NEF and I would bet you won't have to do much to the OEM ejector because of the spring or button as Pilgrim says, which helps grab the rimless case.
I'm not sure why you would go to a rimmed case when you have the equal in the 308W...but that doesn't matter, does it...
...they are ballistic twins and the cases are identical except for the rim on the 307, although the 307 case was supposed to have slightly thicker walls in the bottom 1/3, I've never sectioned or measured one to be sure.
I would forget the 30-30 extractor until after I did the rechamber and fired a few to see how the OEM ejector worked then do the milling. The spring isn't all that strong so if the cases stick you will need a ramrod or mill a section at 90° so you can use a small modified screwdriver as an extractor...someone already has that information available...Fred maybe in the stickys.
Not to make too small a point but I can't figure out why anyone would want a 30-30 AI when you can have a 307/308 in the same package...40 years ago it was the way to go or do a 30 LeverPower, but not today...there are just way to many reasons not to.
Luck on your projects.