In reply to previous questions, I can say that the loopthrough on my HDR-2000T recently purchased from Richer Sounds DOES work when in STANDBY. It does NOT work if the box is unplugged from the mains.
System details are as follows:
Software Version UKTFAC.1.00.07
Loader Version UKTFAC.1.02
System ID 80BC.7E10
Update Date 12 SEP 2013
MICOM Version 12.4
Mac Address 08:EB:74:7D:21:2A