It's my attempt to take the advice and "create what was missing".
I've been discussing this with another user who highlighted the current level of activity combined with those posts renders the default "local" sort relatively useless, so I've already opted to back off until activity in general has picked up to the point it wouldn't be a wall of noise.
The point of the community is to post items available at a discount. Should be more about actual deals than spam. The mods should probably have a rule about self promotion (more clearly an ad) and something about volume of posts to a particular website.
It's a nice idea in theory but just results in FOMO and buying stuff you wouldn't otherswise. Subscribing will likely not save anyone any money. Can be a nice resource to look at if you're going to buy something anyway.
Looks like the bug where the auto refresh will spam out the latests posts from a single community after sitting on the page for a few minutes with the sort being hot, or active or sometimes one day.
It wasn't a bug - it was the natural result of my batching of posting the curated set from the past few hours. It just happened to look a lot like those batched updates from auto refresh.