I can imagine an AdNauseam-like userscript that spams POST requests of fake crashes for every visited webpage (:
If these settings can't be turned off then I'd definitely assume the feature flag reporting and the CSP reporting are used for tracking on some platforms, on which AdNauseam would then have merit.
EDIT: CSP reports are blocked by uBlock Origin by default but it appears there are no browser settings to control this behaviour. I expected Chrome to screw users over like this, but I'm disappointed in Firefox that there's no "advanced privacy options" screen where I can control this behaviour.
Don't be evil (: