Unfortunately no, I just tried that with all hard normals and the same problem occurs, everything skews because transform component only really works in one axis at a time if you want to keep it flat, unless I'm doing something wrong and feel free to correct me. You could of course move the top faces up manually along Y, then use transform component to do the side faces, but that's the same amount of work as just extruding the faces and then deleting the excess which is how I've been doing it in the past.
Neat, what would be the use case for this. We tried to check the UVs from the outsourcing team before we approved them to go on to the texturing stage to avoid costly re-texturing if they had created wasteful UVs. We used the Maya %UV wasted HUD to make sure everything hit at least 70% unless it was something funky where the shells couldn't be packed tightly.