The HD-A2 definitely does not - I've tried to find anything that will allow me to move Jabba's subtitles in Return of the Jedi up into the viewable area on my screen, much to my chagrin. Given the sporadic support for CIH in projectors and players, I'd doubt that many manufacturers consider true 2.35:1 home setups when designing lower-end equipment. The vertical stretch scaling is probably included to eliminate black bars at the expense of strecthing the image, much as people use the 16:9 setting to eliminate pillars when viewing 4:3 material. The subtitle feature was probably included to move the subtitles up into the viewable area so that, while reading, your eyes were focused closer to the center of the image. The Samsung is the only player that I'm aware of that will do this with subtitles (and yes, it's still only SD).
These are just guesses on my part, so take them for what they're worth - but there's definitely a lack of basic support for CIH setups, and that appears to have extended thus far into the optical HD arena. Of course, given the small percentage of the market share that we comprise, I'm not surprised.