Question about Logitech K400 Plus

It will work, but Mac OS specific functions are not supported because there is no support for them.
If it is used to control a home theatre, then it is certainly a good choice. For daily work there is certainly a better solution but not with an integrated touchpad.
I don't use it on Mac as I don't own one, but on Win, Linux and Android without problems.

I use the K400 as an external keyboard with my MacBook Pro. Works perfectly, just remember that by default the shortcuts are the same as on the Mac (e.g. "@" is then also AltGr+G on the K400 as on the Mac and not AltGr+2 as printed) and not as on a Windows PC. However, you can set this on the Mac side if you want (there are many utilities for this), but you don't have to. If you are blindly used to the Mac layout and don't look at what is printed on the keys anyway, you can type away and use the same keyboard shortcuts as on the Mac without having to set anything. The "Windows Logo" key then corresponds to the "Command" key on the Mac keyboard and also executes the corresponding commands, e.g. Cmd-C and Cmd-V for copy + paste..... simply use the "Windows Logo" key. Everything works. :)