Indeed, what you did with this "small update", (Oct. 07 experimental build) is really a BIG thing, A1ex! Screen is no longer dark in the 10/12-bit MLV and RAW recording modes and the pink highlights are gone! This makes the 100D a very usable for practical video shooting camera since now we can see what we record and frame properly during camera moves.
I found one bug though. The RAW_tweak module causes trouble when I try recording with the MLV_rec module. I get the message "Threads failed to start" and that's it. In the RAW_rec module recording works (RAW video is recorded with several 512 byte files) but then, when I try to play it back, I get a black screen and camera crashes. I have to pull the battery out. So, I disabled the raw_tweak module and can now record normally. Sound also works with the MLV_module. There are a few more things that need to be fixed though:
1) Playback of already recorded 10/12-bit MLV and RAW videos activates the counter indicating palyback but produces a black screen, i.e. video does not appear on the screen;
2) I get "hick-up" jumps when recording in 1920x1080, 2496x1080 and 2520x1080 resolutions @5x magnification that produce excellent video quality.
3) In the MLV_rec mode, when I activate the "Moovie crop mode" and press the record button, the BUSY sign appears and recording does not start. I need to turn camera off and on again to be able to record in the Moovie crop mode.
I hope, this bug report is helpful.