Web Compatibility Support • Re: MyNoise’s white noise generator halts loading before finished

True, but exposing myself to adverts and trackers is a red line, and I lack confidence in my ability to rely on DNS-level filtering

The idea is to just use this profile to open a broken website and see if it renders properly on a pristine setup, not to continue surfing on it for any period of time. If it works, then the problem is with your regular profile, if it still breaks then could be a website or browser issue that isn't specific to you. Probably a private window would help to ensure no ad/tracking leftovers remain even from that one page opening.