I don't think that glassing is absolutely necessary, I am doing it for 2 reasons.
1. This is going to be a test bed for another larger scale job I will be doing on a Spitfire. Since this will be mostly on the bottom it won't really be noticeable, if you know what I mean.
2. I know how I fly, so I have no doubt that there will come a time when I will want to fly it off snow. (maybe even grass) I've watched quite a few vids and I don't see any problems with it's design as far as the bottom of the fuse. The biggest thing I see is the tail section and the adverse yaw effect. Nothing a little sheeting and a good set of wires shouldn't be able to take care of.
Shane