Memory data store is not order preserving

A Geoserver user noted the inline feature rendering order is not predictable. This is because inline features are put into a memory data store, and the latter is not order preserving, because uses a HashMap instead of a LinkedHashMap. I'm also wondering if a map is really needed, it ensures no two features have the same id, but it seems a little overkill (its memory requirements are far higher than a plain arraylist).