1) I hope so too! So far no one has offered... I may "bite the bullet" and pick one up used ... one of these years.I hope that you're able to get that loaner RCBS auto-progressive so you can review it and have all of the big four in your article.
[...]can either or both of the LNL and the Dillon 650 be configured so that case and bullet enter the press from opposite sides?
2) as HKMark23 has pointed out, yes on the LNL. I would think not so much on the 650. It would be possible, but the machine is quite busy on the right side and access is awkward.
Here's a pic that shows what I mean. Notice the primer feed tube / blast shield, and return rod for the powder throw:

Another shot. There is room to do it, just crowded:
