I make big use of the reflected binary gray code in my programming, both the bitmap programming and the MIDI programming that I do using your SoftStep (also with CAL). I don't know if anybody else would find it fascinating, but I certainly do. My way of performing what I choose to call the "binary reflected gray code transformation" is to take whatever module is outputting the stream of numbers that I want transformed, and first I use your "Divide" module to halve the numbers. The least significant bit, of course, is lost.
Then, I use your XOR between the original module and the now-halved stream calculated by the "Divide" module. The output of the "XOR" module is the binary reflected gray code transformation" of each original number.
The biggest use I have made of the brgc transforms so far is by taking some brief musical motif created somewhere, and sending it to the MIDI Voice Out module first raw, and then, both delayed and transformed by brgc, then both delayed again and transformed again by the brgc.
You may know that this transformation acts on numbers in different ranges in fascinating ways. 0 and 1 are unaltered by the transformation. 2 and 3 alternate. The integers between 4 and 15 are transformed into other integers that return to the original values after repeated application of the transformation in cycles of 4.
4 is transformed into 6, which is transformed into 5, which is transformed into 7, which is transformed into 4, again.
8 becomes 12, becomes 10, becomes 15, becomes 8.
9 becomes 13, becomes 11, becomes 14, becomes 9, again.
All integers from 16 up to 255 (though with MIDI, we never go above 127) belong to cycles of length 8. All numbers below 128 are members of cycles all of whose members are below 128.