It would also be great if we could snap the rails to the breadboard in either direction. I have a couple of cheap Chinese breadboards with the positive rails on the outsides and negative rails on the inside relative to the breadboard (rather than negative on the left and positive on the right for both rails), and I've found in some cases it can make for slightly cleaner wiring. As it is now, the snapping does sort of work in either direction but it will put the rail inside the breadboard if rotated 180°.
And since we're talking about power rails, split rails might be helpful for some folks at some point. Just something to think about 😊