If you know you like the 4ever, no reason not to get it, even if you end up using it mainly forward facing. For the drop-off lane, it mostly depends on whether you can reach the buckle when she's rear-facing. I could do that with no problem, so it was not an issue one way or the other. But if you can't, then that would be a good reason to switch. If you have to get out of the car to let her out, that's what will cause drop-off lane frustration.
If you do want to switch her, it's a perfectly reasonable time to do it, and then you could consider a harnessed booster that might cost less, though. The 4ever is a bit pricey IMO.