I took some measurements here and it takes about 55ms for the Mini Maestro 24-Channel to update the R, G, and B values and latch them in on a single ShiftBrite using the demo code in our Maestro User’s Guide. To update the entire string of 12 would take about 660ms, though you could do something faster if you reuse the values sent to LEDs earlier in the chain since these work like shift registers.