Currently when

web_profiler:
    toolbar: false
    intercept_redirects: false

is set, the WebDebugToolbarListener is still executed (but disabled). Ideally it should not be executed at all.
Both options must be false because they are indepentend of each other. Its quite irritating that toolbar option maps to WebDebugToolbarListener::DISABLED/ENABLED because its not really disabled either because intercept_redirects can still be active.