Per app eink "optimizations"

[Trender22]

Originally Posted by calliecameron

It looks like mmkv-cli only supports macOS - on linux I was able to make the changes using mmkv's python bindings. Unfortunately it's a lot less convenient.

you may want to try this: https://github.com/timschneeb/OnyxTweaks
it has on-device mmkv editor
it took me a while to make LSPosed to work. now contemplating which app to enable handwriting optimizations for.

[EddyMate]

My device is a Boox Go 10.3 (new) running firmware 4.1, and I found this thread in my search for reducing handwriting lag in my FOSS apps which save their note files in an open format such as gzip compressed SVG. (The handwriting note apps I want to use are Write 3 and Saber, although I still need to find their appView names.)

I haven't rooted my Onyx Boox Go 10.3 yet, but I noticed something interesting.

I found (via non-root adb shell) that my onyxconfig/mmkv/ directory and the files there all have world read-write permissions -rwxrwxrwx:

Go103:/ $ ls -ld /onyxconfig/mmkv /onyxconfig/mmkv/o*                           
drwxrwxrwx 2 root   root      4096 2025-10-03 23:00 /onyxconfig/mmkv
-rwxrwxrwx 1 system system 1048576 2025-10-03 23:09 /onyxconfig/mmkv/onyx_config
-rwxrwxrwx 1 system system    4096 2025-10-03 23:09 /onyxconfig/mmkv/onyx_config.crc

(I can create test files in the onyxconfig/mmkv/ and I can read/write such files, although I could not delete files I create there; lsattr shows the e attribute set, for extents, so perhaps this is the reason files cannot be deleted from the directory.)

Not sure if the world rwx permissions on and inside of onyxconfig/mmkv/ is a 4.1 firmware oversight, or deliberate.

I am tempted to start tweaking onyxconfig/mmkv/onyx_config even before rooting, but I am thinking it may be safer to root the device first before playing with this config file (to reduce chance of bricking).

[Renate]

Rooting may be a good idea.

If not, use EDL and make a full, raw backup.
Yes, it will be 64 GB, but it will allow you to return to exactly where you were.
It might take 45 minutes but you'll be back to the page that you were reading.

[EddyMate]

Thanks @Renate. Yes, I should at least take a full raw dump before playing with things.

I wonder if the OnyxTweaks mmkv editor (mentioned by @Trender22 in post #31) can be used without root on Boox devices running FW 4.1.

[timschneeb]

Originally Posted by EddyMate

Thanks @Renate. Yes, I should at least take a full raw dump before playing with things.

I wonder if the OnyxTweaks mmkv editor (mentioned by @Trender22 in post #31) can be used without root on Boox devices running FW 4.1.

@EddyMate Hi, I'm the developer of that app. I've added support for that just now. Version 2.2.0 supports editing the mmkv stored at /onyxconfig without root