Splitting induvidual WS2812B LEDs
If you have "dumb" RGB strips that require 3 PWM signals, you can get WS2811 chips individually WS2811 @ AliExpress.

If you get LEDs that have WS2812B chips inbuilt (note: they don't need to be in a strip, they can be individual) then you just route the signal from LED to LED around your case.