Gil - the challenges are 1) the step edges will all disappear under light and 2) we need to spike specific places on the set without breaking up the all-white aesthetic.
Yesterday was our first day on the set. So far, off-white tape is helping, along with reverse, small dance numbers (black on a white card). But spiking marks is already a problem - we labeled DC along with footmarks for two major scenes with white tape, and the actors keep floating anyway. However, we are finding some creative solves, including glow gaff, and glow tape spikes, which appear yellow-y but don't read to the house. Yay!