Good point on the shavings. My home-made plane has the square peg and it's a bear to get the shavings out.
In fact, I think that shavings may be one of my problems. I think the 'front' angle is too steep, making it hard for the shavings to clear, causing a jam.
My next plane will have a more relaxed angle on that part. Assuming I keep the mouth size the same (small), can anyone think of a reason why I can't have a wide open 'front'? I cut the front with two angles, one steep right at the mouth so that the mouth doesn't open up when I sand/flatten the sole, then another more shallow angle that gives me room to get my fingers in there and for the shavings to clear....