Hey,
I think you're understanding it correctly, as soon as it reaches the dirtiness threshold that you set it's supposed to trigger a janitor to come and clean it. I just gave it a test and it was working correctly for me, *however* the "stinky fume" also appears at whichever threshold you set which seems confusing. I've changed it for the next update so that the fume only appears whenever guests think the dirtiness has reached a disgusting level.

Thank you! That's really helpful. I just realized that the fumes thing as well which was part of my confusion.

I watched my stalls go through a few rounds of getting gross and realized the assignment appeared to be working on toilets and hamburger stalls, but never on hot drinks, pretzels, and cookies: those didn't trigger a clean until 75%. I thought that was strange, so I tried wiggling the slider on my hot drinks stall, and it worked after that.

Hamburgers were the first food stall I built, so I thought the problem was sync was only working across food stalls of the exact same type (like how pricing works).

Built a new hotdog stand and while it appeared in the window to inherit clean at threshold of the of other food stalls, it didn't work. Manual adjustment made it work. Built another hotdog stall thinking it would inherit as the same type, it didn't. So that killed my previous guess on stall type. Built a new toilet (because I was convinced all toilets were working with sync but wanted to be sure) and it didn't work either. I must have manually set some things across the way.

Short of it is, it seems that the sync settings in the UI aren't sticking for me with this setting. For now I'll just set each toilet and stall manually and not use sync. :)

Thanks for the repro steps!
Turns out... yeah, the synchronized threshold wasn't working correctly :|
Will be fixed with next weeks patch!

That's so awesome, thank you so much!