Would be helpful to be able to set custom drive size when map / define a drive (on the desktop edition once you've registered).

Currently it just shows the same size as the underlying drive & says that it's used the same amount of space as the underlying drive. This is confusing as you've actually added less than this to the encrypted store. (It seems "accurate" when your using the trial / free version that has a limited drive size). I assume it takes this approach so that the remaining space in the encrypted store is accurate.