A sub-hilt is an exercise in advanced fit and finish. Like Doc says, they can be rather uncomfortable in use, but they do look cool.
I think the key to a comfortable sub-hilt is making the rear guard narrower, side to side, than the forward one.
What have you got to lose by trying? Not much really. However, the process of putting all of that together so it works, feels comfortable, and is finished well will teach you things and grow your skills. If you do choose to go that route, I would very much like to watch the process.