How can I know if the updates have already been applied? Just explore the settings?
There should be something in settings that says what firmware date it has.
That itself varies by manufacturer, so I’m uncertain where it would be menu wise.
Could even be a string of numbers on screen somewhere saying “V.date or version number here”
The player I grabbed for my girl years back has the latter, version is on lower corner of menu screen.
More recent ones I expect it to actually have an option in the settings somewhere to say what it has.