like most open source-projects, there are quite a few features that get started and then need to be disabled until they're mature enough to use.
In the case of the "Add" button, difficulty in come up with a simple window-management system meant that I disabled the feature - but left it in place as I hoped to return to it.
In the case of "Save", I hit serialization issues due to the addition of a plug-in architecture and the serialization features in .NET not supporting interface based deserialization easily. This problem has been solved and saving will hopefully
return when I next get time to work on it.
Exporting to a file isn't the primary aim of Sentinel as the logger source (such as nLog or log4net) could easily be used to additionally create a persisted log. There was some basic functionality in this area but I don't imagine its completion to
be a priority due to the being able to do it much easier at the source of the logging.