I've worked my way around this by writing the following AutoHotkey script
$^c::
Send ^c ; Do a normal copy to clipboard
sleep 100 ; Wait for the copy to finish
WinGet current_application, ProcessName, A ; Get the name of the current application
; if the application is OneNote, and the copied content is text ...
if ((current_application = "ONENOTE.EXE") && DllCall("IsClipboardFormatAvailable", "uint", 1)) {
clipboard = %clipboard% ; remove the formatting
}
Return
This script detects the current application, and type of content being copied. If text is being copied from OneNote, it stores the text in the clipboard as plain text, removing the other types, causing a paste in other applications to work as expected.
The advantage of this script over the other solutions out there (that remove the formatting when using Ctrl-V) is that copy-pasting of files/images/formatted text in word, doesn't break down.