This request is extremely basic in regards to the other feature requests I have read, but I am not experienced enough to even understand a lot of the other requests.
On the Communication tab there is a box to enter GCODE type commands. GCODE is limited to only uppercase letters, so, why not just have Simplify3d switch the command to be uppercase if it is entered in lower case? The main reason I suggest this is that many times I am on my computer while the printer is printing something, or I am simply trying to do two things at about the same time and find that using the cap lock key ends up being left enabled and now I have to re-write some text because I did not intend it to be uppercase. It is a fairly simple request, with very little exposure to the main code, so chances of introducing bugs is very low.