Hi Elias,
It is very much on the roadmap and we will get to it as soon as we can but we are a small team and have several things we need to work through before this can happen.
Xerte Online Toolkits is available on Github for all to access the source code and if you are a programmer then please feel free to fork the repo and attempt this yourself. as a hint you should probably look in the xenith.js file (search the repo for these files and folders) and see how the tracking works just now for Scorm. The methods all begin XT. Then locate the scorm folder and have a look at these files to see how they receive XT commands from xenith.js This should give you a start at thinking about how it would be possible to implement xAPI.
While you could log accesses to each page from xenith, you will need to look into the models_html5 folder to locate the individual page models in order to store specific text or data. Some of these, quiz and mcq, already do this for question scores.
Send us a Pull Request via Github if you manage to get something interesting working as it is a much asked for feature.
John