My FTP went down relentlessly whilst following the Zwift FTP builder plan. Was dispiriting. I ended up getting a bit of coaching. He basically looks over what I do via training peaks, sends me PMs via facebook, and we go for coffee every 6-8 weeks. He mostly sets me TSS and intensity factor goals, but recently has been getting me doing all out sprint intervals a few times a week.
I use Today's Plan rather than Training Peaks, and I don't have WKO, so can't see all the metrics he looks at. However, I am pleased with the progression in 60m w/kg.