I've asked two questions here https://unix.stackexchange.com/ but it looks like there aren't that much experts of KDE Neon.
My trouble with systray icon is https://unix.stackexchange.com/questions/527965/ibus-m17n-systray-icon-disintegrates-from-systray
and trouble with AltGr is https://unix.stackexchange.com/questions/527879/altgr-isnt-working-with-ibus-m17n-in-kde-neon