Just a tip that could save you some time. For magazines that are glued (not stapled), put the magazine opened down the center face down, spine up, on an ironing board, lay a thin towel over the top, and use an iron on about medium to melt the glue. Then the pages can then be quickly removed before the glue sets again.
That's a good tip. I have a scanner with a document feeder. I would remove the covers and scan them separately. Then using a metal ruler as a straight edge, and a sharp utility knife - cut the spine off. Then all the pages go through the ADF.