Dave,
I had to splice hoses for my upper & lower radiator hoses, and both have the Gates heat shrink clamps on sleeves with no bump. No problems do date. The one thing I learned is that it does not take much heat to shrink them. I slipped these clamps on my radiator and heater hoses to use at the ends, but I wanted to be sure I was ready for a permanent installation since they have to be cut off so I slid them up on the hose leaving room for regular clamps. After a few dyno pulls all of the "temporary" clamps were shrunk in place by the heat of the hoses, creating minor restrictions by squeezing the hoses down I had to cut them all off, and to date I have not gone back and broken the lines apart to put the fancy clamps on. They really do look clean, especially if you clean all of the green print off of them with lacquer thinner before you put them in place. Just be sure to shrink them fully with a heat gun.