(op here)
I typically deal with dots at the same place as a single dot and, when clicked, open an infowindow/infopanel that will let people see all of the points’ data.
ie you do need to deal with this issue (by default, no mapping library will do it for you) - and most clustering librairies (or at least their default settings) will also not solve this for you.
The ui for what happens when a point (or even a cluster) is clicked but that point contains more than one point’s worth of data is its own separate problem basically
Does it end up a darker or at least fully opaque dot to show it's not the same as the individual dots elsewhere? Like from your example in the article, I might make that dot maroon (or some other color entirely) instead of red so people understand "there are multiple things here."
This has been my first adventure dealing with maps with user-generated points and I'm discovering how much goes on behind the scenes that I never noticed!
It’s not easy for sure and I’m not a designer or ui/ux expert - just been around maps for a while
I agree with you that the point itself could show that it’s special - or - rely on users tapping/clicking it and then show all the info
In a sense, maybe conveying that the point has more than one data point attached to it isn’t critical - as long as you can see everything inside when clicking it!
Feel free to email me, would love to jam/chat about this!