Question about Logitech K280e

Depends on what you mean by programmable. Under Windows 10, the default programmes selected by the user are used for the function keys (music, browser, etc.). Unfortunately, I cannot answer your question about Linux. As a Linux user, however, it should be easy to freely assign any key assignments to all keyboards. Solutions for this can be found on the Internet.

With Logitech SetPoint, which must be installed separately and is available for Windows and Mac, 6 of the function keys can be configured as desired (e.g. launch an application, open a website or execute a key combination).