Filter reading performance
Reading an INI file with some filters is too slow.
The (main) reason is that a Replicator replicates the whole huge filters XML node into a dropdown list showing the list of filters. Clicking the + button to add a filter takes about 1/4s on my machine. This dropdown list (""Alternative"" panel) builds the whole node and shows only the current selection; i. e. there is no delay selecting a filter, because the GUI for it is already available (but hidden).
It looks like this has to be rewritten in a way that the dropdown list builds from XML only on demand when selecting an option. This is a bit annoying because the ""Alternative"" panel is the most delicate of the lot and needs to be changed fundamentally...
Side note: Other than that, profiling does not really show anomalies for the logic, even though it is a little convoluted (because a Selector can create a Replicator that creates a Selector that... until the panel for the actual INI key is finally available).