My 12" MacBook has the Chinese (Simplified, Pinyin) hardware keyboard and it has the default function on Caps Lock that lets you switch the language input between Chinese and English.
However, I also use Japanese, Korean and Russian keyboards and found out that the capslock doesn't let you switch between Chinese and English. It just switches to the last used keyboard. So for example, if you type in English, switch to Korean, switch to English, and tap on the Caps Lock, you get the Korean keyboard, not Chinese.
I always want Chinese keyboard on whenever I tap Caps Lock. Is it possible on macOS?