Not that I have tested this extensively, or much at all, but here is what just “worked” with the AltMill at Idle.
I put a 1000uF (did not have a 100uF) capacitor across the + & - nearest to the LED strip on the X axis.
I put a 330 ohm resistor on the data line at the connector coming out of the SLB. (Polulu said 100-500)
This enabled me to use Q0, Q1, Q2 and visibly see the entire strip light up and respond to commands.
I entered M356 P0 Q0 and the hit the E-Stop and all 60 LEDs turned red.
Upon clearing the E-Stop, all returned to white.
Not sure of you have any of the components lying around but you might try this.
Also, not sure the capacitor was needed… I initially had the resistor near the LED strip and this resulted in various behaviors of the lights, some on some off (sometimes), rainbow colors, and more. When I moved it to the SLB side, then it worked.
Also - I did not trim my wires any but will before I solder this all up and finish installing. Meaning that I have at least 12’ of 22awg running with the above configuration.