The harmony can record any IR signal you can show it. I am trying to get them to be able to accept any pronto code too. The website can do you discrete codes without delving into XML. The harmony can even do input cycling properly if taught. it remebers what you were using and how many cycle commnds it needs to get to the input it needs.
I am slowly phazing out my original remotes, but every once in a while I find there is a command that does not work, work properly, or is not there. I add it to my harmony web site and with the next update it works.
I have delved into the XML, and I feel that it's really necessary to do some of the more cutting edge stuff ( see discrete programming example ) but the website could have done it just it too, just not quite as clean as my method.
The last magor update that I did was my navigation commands for left and right were backwards for my DVD, I poped into the the language learner and fixed those two buttons. All without touching the XML.
