On Linux, one is able to input arbitrary Unicode codepoints by inputting ctrl+shift+U, then the hexadecimal codepoint, then space or enter to confirm. This is generally done at a level outside of the game, as this input is handled by the system, so, at least in GNOME, a small popup window appears at the bottom left of the window you are typing in. As of recently (1.19.3 is affected, as is 1.19.4, and I am not sure exactly in which version this behavior began.) this no longer works, instead not creating a popup and not inputting unicode characters. This can be an issue for users who have keyboards with keys that do not work, as mine currently has the brackets/curly brackets, colon/semicolon, and backslash/pipe keys unbound, so in order to type these characters, some of which are very important in commands, I used to be able to just input the unicode input sequence, however now I need to type them in another application and copy them into the game. This also could affect users using QMK firmware on their keyboards, a very common firmware that uses macros to input non-standard unicode characters when no keycode exists.
2023-04-07 14-42-38.mkv Attached is a video in which i type ctrl+shit+u, then 3a, which is the codepoint for the standard colon, : Note the popup at the bottom left of Geometry Dash but not Minecraft.