Channelling pays experience for accuracy: a kept beat earns, a mashed one earns nothing. Practice with no target still counts — it costs vigour, which is what practice is.
What a level buys
Each level lowers your own resistance r, halving the
distance to its floor roughly every five levels and never quite reaching
it. Everything gets cheaper and the light answers quicker — but a lower
r also walks you toward the burst threshold, where driving
hard into a small load stops being bright and starts being dangerous. See
Channelling for the law this
plugs into.