nobody will yell you if the treatment time increase. ;-)
definitely idividually for each provider
I will not make a separate menu item that will "on" the channel logo update logic ... Everything is simpler ... If you "on" - "Download channel picons" - then new ones will be loaded and existing ones will be updated ... If you "off " - "Download channel picons", then the existing ones will be used .. I see no reason to "clog" the provider's settings card with unnecessary logic