Karelia
Let’s start by talking about images I found – there are two and for some reason they depict two different renditions of already an early map proto.
The whole map just feels off. Firstly, central field is gigantic and it seems like its additional surface was taken from medium (upper) flank which in this version has pretty much nothing on it.
As for heavy flank, it seems like the balcony is just a flat passage to central area, as opposed to being elevated like at release/currently. Moreover, it seems like distances between mountains on heavy flanks and hills where bases currently are is way bigger too. For last, there are few big rocks on heavy flank, making it pretty much completely different to how it’s played currently, but a bit similar to how it’s played currently when random event happens.Now for the 4th image (the darker one). This version seems much closer to the current one, with most proportions of objects and distances between them being somewhat in tune with current state of things. One key difference however is that heavy flank is way more open, once again taking that additional surface from upper flank. Moreover, now there seems to be no balcony at all, turning the additional big rocks on heavy flank into high walls with a narrow passage like on Oyster Bay heavy flank (ignoring recently added cave).
Prokhorovka:
Its pre-release render (1st image) doesn’t really show any differences to release version, but release version shows one big difference to the current one – at first, Prokhorovka map was rectangular, not square, as seen on a very old minimap (2nd image). This was changed to current state in Update 0.2 closed beta, in March 2010.