I'd like to make controller modules to drive single color "dumb" LED strips using an Arduino that could be daisy chained and addressed in the same way these P9813 controllers are. So I'm basically looking for single channel version of P9813.
Does that exist?
Why? What prevents you from using P9813 with 3 channels, but instead of 3 different LEDs, connect 3 LEDs of the same color? Or use PCA9685 and drive 16 LEDs with 1 chip but PCA9685 is controlled differently.
Well at just a single FET it is hardly worth putting it on a board.
If you are so allergic to construction why not just use one part of the P9813.