Just in case any of you wanted to scrub, while your RTD is in record arm:
Here's my setup.
*master - aux
#RTD# - Audio Track where the mix is recorded to
scrbsnwvfrd (Audio Track) and *scrub (aux) are normally hidden
On scrbsnwvfrd I have a 1000Hz sine wave (peak at -0.9dB) group (appr. 2.5s) repeated for about an hour or so.
Hope this helps,
Timothy