Project files have been updated to version 12.1 (codename: “Gigawatt”), and the first post has been updated. Please PM me for temporary download links until the files are available at some more permanent locations.

Rough summary of changes from 12.0 to 12.1:

Improvements to Turkish subtitles (thanks to ArdaYlcn)
Turkish titles-only subtitles updated to accompany new Turkish dub
Improvements to Korean subtitles (thanks to Kaz47)
Czech titles-only subtitles included to accompany new Czech dub
Persian/Farsi titles-only subtitles included to accompany incomplete Persian/Farsi dub
Project Threepio is now theatrically synced rather than GOUT synced, because all major Star Wars preservations now plan to move to theatrical sync – while having theatrical sync doesn’t break subtitle compatibility with the existing versions. In practical terms, this makes no difference at all, since a difference of a few frames means nothing for subtitles.
Added support for the 70mm cut of Empire. I don’t currently know of any restored 70mm prints or full-film 70mm reconstructions for Empire, but if/when one exists, the whole world should be able to watch it (thanks to morgands1)
Updated Noto fonts to more current versions. Most significant changes: Arabic available in semibold weight, Hong Kong CJK variant available. Lots of minor fixes included as well.
Graphical Italian alien subtitles for Star Wars (in the style of the original theatrical 35mm Italian prints) are now based on 35mm scans, rather than approximated with a custom font (thanks to williarob)
Project Threepio now includes more Windows binaries for portability, allowing most operations to work on the Windows platform without installing any software at all
Fixed several multithreading-related bugs in the scripts
Fixed some posterization that would result from subtitle colors being reduced for the indexed PNG format required for subtitles. This was most noticeable in the 35mm alien subtitles, which included lots of subtle color variations. Everything is now properly dithered, and the unmodified PNG32 files are now included for use by preservation projects.
Some scripts now support a -yuv flag to compensate for expected color shifts from an RGB-YCbCr-RGB round trip (i.e. they make the colors a little wrong, so that after they’re encoded as a BD-SUP and displayed during playback, they’re approximately right again). All included BD-SUP files have been created this way. These color shifts are extremely small and typically unnoticeable for a single round trip, but since Project Threepio’s instructions for some tasks can include multiple RGB-YCbCr-RGB round trips, they can add up to something noticeable unless compensated for.
Python scripts now require Python 3.6 or later