I said appears since all I did I look at the announcement thread. It's noted as being turned on and off by builders. In the past on s5 this had to be done on some ROMs and I was pretty sure havoc was be one of them. There is definitely sources at GitHub repo that list call recording options, record file location ect. I didn't read enough to know if it can be enabled on all builds.
Also I hope you were offered the v20 by the guy who said he wanted to donate one for development purposes. It would be nice to have havoc, aicp, or crdroid on that!