I know that it's not a looper, at least a traditional one,
but if you read the Info page, it says : " Looping available w/multitap fdbkdly..",
I've set the Fdbk value to 100% on the Multitap page and Fdbk Level to 99% on the Master Parameters page (99% because it's the maximum default value allowed).
With VSig, I've changed and adjusted that fback level from -99%/ 99% (default) up to -100 or 100% but there is not and an endless delay, it decays after 1 minute circa.
I don't know why