2 speed fixie

Went at my local bike shop to get a new chain
And my guy was so happy to see me he just finished his 2 speed fixie something ive never seen. He said its a old german gear. Want yall think. He let me test it to clutch in the 2 gear you need to give a lil kick backward n it shift all that and you can break at the pedal its wild honestly. He was building another wild thing a Mountain bike with a gravel front end but lock suspension ill take a photo when i get my bike back !