Ok i found out that on OpenPilot there was a file called "poilearnsettings.cpp" this one doesnt exists anymore...it seems that in OpenPilot you could use an Accessory channel to store a POI and this file does this job...You still got the UAvObject "POILearnSettings" under System but I think its not usable by now...and im too stupid to implement the old CPP file :-)...
It still exists, it's a synthetic file that's generated when the code is compiled. It contains the code to access the fields in the POILearnSettings UavObject. It's not used anywhere and the xml file may have been added by someone who planned to use it but never did. It was last changed back in 2013.
Looking at the xml I think it's intent is probably the opposite of what you think, it appears to be intended to turn on an accessory when a POI is reached. Probably something like fly to this location and turn on the video camera or take a still picture.
Your video is great, we lack good documentation on a lot of the autonomous flight things. Write some documentation, it doesn't have to be polished and perfectly formatted. f5soh is really good at reformatting pages to make them look nice.