Although it's not easy to do with our APIs at the moment, it's theoretically possible to log a non-splatted element with a single instance-key.

For example, a future API that allows us to log colors directly:

rr.log_points("points", [[1,2],[3,4]], instance_keys=[1, 2])
rr.log_colors("points", [RED], instance_keys=[2])

In this case, color is not a splat, but if you hover on the batch of points in the UI, it will display as if RED applies to the whole batch rather than only applying to the 2nd point.