Gave a huge skim but didn't see any documentation on the features/patches of the TWPatcher? Is there one floating around? Obviously I get/understand all the display/filter modes, Its just the various patches/RTCOM stuff.
There isn't any documentation, sorry. It's hard to document patches; or at least I haven't figured out an efficient and useful method.
Un-START reverses the role of START and SELECT during boot-time, so instead of pressing START *or* SELECT to disable stretching, you have to hold START *and* SELECT to enable stretching.
Redshift is a port of CTR_Redshift to TwlBg. It shifts your screen to be more red (or "warm"), or alternatively to be more blue (or "cold"). Useful when playing a lot at night, because it helps on your eyes.
DMPGL is the name of the OpenGL driver for the PICA200. I have to patch the GPU driver itself to be able to get widescreen, but I also have to patch the MTX driver (the capture card's driver used to transfer DS/GBA display to ARM11) to be able to get widescreen.
GPU scale test is what it sounds like. Normally the upscaling is done by the capture card hardware using very simple math, but it's low quality, and is generally really phinicky to get working. The patch patches a lot of the graphics drivers and graphics software to be able to get the GPU working instead of the capture card doing it.
The reason it's so difficult but not impossible is because there is a flag which tells if the scaling should be done by the GPU, but it's almost completely unfinished, so I have to basically implement what Nintendo didn't implement using existing code space which I can't change or expand... yeah.
The exception handler is not that useful, it's just a PoC, and nobody has the kernel patches yet, because TWPatcher doesn't have a kernel patcher yet. If you had a patched LegacyKernel11, then this patch would reinstall exception handlers which weren't fully removed from LegacyKernel11. It's definitely useful for debugging rtcom payloads.
Anti-DPAD patch just removes the DPAD filters, meaning that you can press LEFT+RIGHT or UP+DOWN using the DPAD and the CPad. This patch is necessary, because on unpatched TwlBg and AgbBg these aren't possible.
The hole patch is just a test trainer which runs every frame. It changes between versions, and it's no use to anyone besides me.
As for the "???" patch, I have no idea either. It doesn't seem to do anything...