I'm a shorter rider with a short upper torso. My current ride has a 50cm c2c seat tube and 52cm c2c top tube. I have always felt that I might benefit from a custom frame with a longer seat tube and shorter top tube as this would let me ride with a stem with a shorter stack height and shorter reach.
My question though is, would such geometry even be possible or practical for a road bike? I have noticed that typically bikes in my size usually have the top tube longer then the seat tube. What I had in mind was more of a 52cm seat tube and 50cm top tube.
In principle there isn't anythign wrong with it. There may not be a huge gain either. I'm bigger and only custom make my own rides, so i and not sure of what happens in your size range. The issue would be what happens to wheel base space, and if anything weird gets compromised to allow the change you want like maybe head tube angle. When working out my own designs I draw them up in CAD.
If that is what fits you, then it won't be a problem. as nessism said, there will most likely be significant toe overlap depending on the rest of your geometry. Depending on how you intend to use the bike it could be of little importance to you.