stow them by 60kts.
Not right. The instruction is to start reducing reverse power at 60kts and go to fwd idle by 20kts. You should leave them in reverse mode until you are absolutely certain stopping is assured in case of brake failure, so there is no harm in leaving them in reverse idle until 20kts just in case you need them. I find I have to convince several new pilots you should do this as they get very nervous about any reverse below 60kts- they all want to frantically cancel it too early.