I have unpacked and decompiled the full contents of XXMS1 in order to compare it with XWLSD, in a similar way to what I have previously done with XWLSD vs XWLS8.
The differences I found were all in the exact same areas as previously listed, but in the reverse direction. Meaning: what LSD introduced as improved over LS8, is now reverted in MS1.
Examples:
- gannet "removed"
- no handling the Indian and Thai vowels boundary when selecting text
- no handling of audio pausing in HTML5 when losing focus
- older version of Polaris Viewer and Samsung Apps
- Turkish specifics in the Samsung keyboard
- Samsung calendar
etc.
Some other things I mentioned before are NOT different in LSD vs. MS1, such as:
- Launcher handling of certain shortcut types
- talkback option in setup wizard
etc.
Most of the changes are however "gone".
This means that from an evolution perspective MS1 is somewhere in between LS8 and LSD. Not purely from the changelist point of view, but from the code itself. And it's very close to LS8, not so much to LSD.
I no longer have the LS8 contents unpacked and quite frankly don't think there's any point in redoing it, but for pretty much all purposes XWLSD is later than XXMS1, which is almost the same as LS8.
As for the CSCs, they are different (BTU, DBT, ITV, XEO, XEF, KOR in XXMS1 / AUT, CYO, CYV, DNF, EUR, NEE, ORG, ORS, TPH, XEZ, XSK in XWLSD from NEE) but the CSC-specific configurations are negligible.
Settings such as APN list are applied even with a foreign CSC code.
My advice: stick with XWLSD.