the google search said 8 degrees is possible, but never mentions [,,,]
Consider avoiding search engines that summarize search results.
In "new brewer" troubleshooting topics, new brewers would often ferment in warm (e.g. 70F with A/C running) apartments with no other temperature control. Responses would claim the fermentation would be +5F, +10F, or more above room temperature. This is likely the source for any LLM generated "search summary" response.
CB&B web site had an article a couple of years ago (I couldn't find it today with a quick web search) that went into the idea in more detail.
eta: looks like the site has moved a bunch of content behind a 'wall' (so bots can not access the content?)With a modified "swamp cooler" approach (and 2 or 3 gal fermenters), I find that water temperature in the cooler matches fermentation temperature. When raising or lowering the temperature of the water, I find it takes an hour or two for the wort to reach that temperature.
If you have specific links to human generated content related to +8F, there may be more to talk about. Otherwise fermentation temperature control techniques as simple as a "swamp cooler" often result in +1F (maybe +2F) variation during fermenting.
edits: formatting, more failed CB&B site search attempts