Although, it must be asked, if QE works… then why are Central Banks doing it for a 2nd, 3rd, 4th… nth time?

QE simply swaps bonds for reserves. My worry is about the quality of those bonds, especially those mortgage related. Since the Fed shares a balance sheet with Treasury it would be possible to launder less than top quality mortgages through such bonds, similar to our issues of '08 except with less fan fare. I've been waiting for the other shoe of retail/business mortgages to drop, but maybe it is coming in for a softer landing via QE.