It appears you found a glitch in the Action Condition processing. I passed the information on to SHN support for their evaluation. You might have found working with the xml directly to be more to your liking. It makes one responsible for the correct xml syntax but perhaps easier for someone looking for a more program oriented approach.
How did you code an X10 50% dim in your previous technology. I replaced all but a few relay based X10 devices with Insteon years ago but don’t remember any X10 command that would support a 50% dim request. It has been some years so I may just not remember the command sequence.
EDIT: the Harmony client does show X10 status on nearly an instantaneous basis. The HTML interface does also but with a few second delay associated with refreshing the HTML area screen.