Interesting version of a Munter tied off. I learnt the 'Super Munter' which locks the Munter by taking the tail around it to lock and a bite up through the carabiner, then the bite ties off with half hitches below the Munter. Same principle. Can do a zero slip release.
I abseil on a single rope unless pulling/last one down. Rigging a releasable is easy once you know. I like reason #1 in the video!