Yes here's the contents of the hgx file Mike posted back in May. You can clearly see the RF Send command format is incorrect. I'm now puzzled as to where he got his information from. It shouldn't be too difficukt to find this out. I'm going back to the Homegenie GitHub to the point where Gene introduced support in HG for RF Send and work from there.
{"ConditionType":"OnSwitchTrue","Conditions":[{"Domain":"HomeAutomation.X10","Target":"A15","Property":"Status.Level","ComparisonOperator":"Equals","ComparisonValue":"0"}],"Commands":[{"Domain":"HomeAutomation.X10","Target":"RF","CommandString":"Control.RfSend","CommandArguments":"20-60-9f-20-df"},{"Domain":"HomeAutomation.HomeGenie","Target":"Automation","CommandString":"Program.Pause","CommandArguments":"1"},{"Domain":"HomeAutomation.X10","Target":"RF","CommandString":"Control.RfSend","CommandArguments":"20-60-9f-20-df"},{"Domain":"HomeAutomation.HomeGenie","Target":"Automation","CommandString":"Program.Pause","CommandArguments":"5"},{"Domain":"HomeAutomation.X10","Target":"RF","CommandString":"Control.RfSend","CommandArguments":"20-60-9f-00-ff"},{"Domain":"HomeAutomation.HomeGenie","Target":"Automation","CommandString":"Program.Pause","CommandArguments":"1"},{"Domain":"HomeAutomation.X10","Target":"RF","CommandString":"Control.RfSend","CommandArguments":"20-60-9f-00-ff"}]} [] HomeAutomation.HomeGenie.Automation 1014 Modem Reset with A15 OFF command cm15 xmit RF A1 off, wait 5 sec, then A1 on - if powerline A15 off received (reset modem) X10 false 2019-05-07T13:03:18.352555Z 2019-05-07T13:03:26.243875Z Wizard true