As I stumbled upon an add-on to control the Spotify web player from a keyboard, I noticed that sites like Wikipedia are using so-called access keys to up/downgrade users experience. That is alright until I can not find a way to block specified access keys from websites or even change them. In Firefox Alt + Shift seem to activate those access keys. Hence Alt + Shift + P is my desired shortcut to stop and play the music within the web player, but is conflicting with the same short cut on wikipedia.com
Is there any way to permit or change access keys from specified websites for good? I don't have much understanding, but cookies won't be the solution since they are cleared on a regular basis.
PS: I very much prefer a solution without extensions