Tell us about yourself!
Nice idea. Thanks for posting.
Spill here means to change shape. If you take the marlin spike hitch, and while it's on the spike, push on one of the loops, it will slide around the knot to the other loop and form the new variant. (You are not sliding along the spike, but sliding one loop around another on the knot.) You can think of it as the same knot, but different configuration, although it will act differently.
Impressive, especially how round you cut that hole with the angle grinder. But what happens when someone in the house goes looking for that vacuum cleaner?