Is there a way to separate clusters in UMAPs using circles, outlines, borders, etc.? I have seen this in some presentations however cannot find documentation for this feature and would appreciate any input.
Do you mean something like the image below? If so, I think you will have to write a custom function - at least I did it. I don't think it matters if the circle or ellipse is not perfectly enclosing the dots, as long as you do some clustering beforehand and color data points accordingly.