I think a Despecialized Edition without subtitles for the alien speech would go against the purpose of the Despecialized Edition’s mission.
Indeed. I completely understand the desire to have it look right in one’s native language. But a good amount of work went into the making and rendering of the text by (at least) Harmy, Catbus, and me. And it can’t be pulled off as effectively with a subtitle stream alone.
Maybe Catbus can answer: Are there packs of subtitles available for just the Greedo text (presumably rendered in the top portion of the screen) that people could mux in with their dub of choice?
Actually, most dubs just dub over the Greedo and Jabba lines, so no subtitles are needed in those languages. For a few languages, though, they do not dub over those lines, so those lines would need to be subtitled.
Project Threepio includes “titles only” subtitles in these languages, which subtitle only the Jabba/Greedo lines, and/or the crawl and other onscreen text like the tractor beam controls. They are designed to go with the English video and the dub. To work around conflicts with onscreen text, the subtitles are shifted to the top of the frame (so for Greedo/Jabba, you’d have two sets of subtitles, with the one in your language at the top of the screen). It’s not ideal, but it works to provide subtitles without compromising the theatrical fidelity of the Despecialized Editions. As far as I know, these movies were never shown theatrically without some sort of burnt-in subtitles during the Greedo/Jabba scenes.
Utilities are included with Project Threepio to shift these subtitles back down to the bottom of the frame, to accompany subtitle-free video, but you’d have to get the subtitle-free video elsewhere. Also, for a few lucky languages, we have subtitles designed to match the font, size, and placement and exact original text of the subtitles that ran theatrically in those countries, wherever we have a reference. But again, you have to provide the subtitle-free video to overlay them onto (or just get the German/French/Italian versions of the trilogy when they’re available).
If you’re curious, download the complete Project Threepio. It’s a lot more than just a bunch of SRT files. Follow the link in my signature for the project discussion thread.
EDIT: yoda-sama is right. Seamless branching is the only technically correct way to address this problem, allowing theatrically faithful burnt-in subtitles for some viewers and not others. But it’s very hard to do right, and we have plenty of projects that simply do alternate video altogether to achieve the same thing.