Hey guys,
1. I bought X_M2S with stable-15 and updated to stable-18 through Updater (to system 2);
2. Then I downloaded dev-3.7.5, renamed to 'update.zip' and flashed via Recovery (to system 1);
3. Used 'Factory Reset' to fix minor issues (dev-3.7.5 is still present active on phone);
4...