yeah I do this all the time
not for the feedback stuff though (but it works, you can use the analog simulation for that too, or tape echo)
but because of the other possibilities :
I play something with a short delay, but step on the tap tempo just once at the beginning...
I step on it again at the end + turn the feedback up -> loop
then I can switch to another patch and do the same. I can even programme the exact number of seconds of the second loop to be half, or third... (if I'm lucky) of the first loop, and have 2 loops of different sizes in one another. or if they don't match, what the hell, every run seperates them a bit more : CHAOS!!
I told jamie he should try to use it again before he sells it!! the dd-20 is very bad marketed (?) it has amazing potential.
From time to time I send Dwight faxes. From himself. From the future.