For situations in which a small number of distributions – ideally 2, but a couple of more is probably acceptable – are being compared with quantile dotplots, I'd really like to be able to put arrows (or lines) between dots representing the same quantile.

I think this would make it clearer if/where changes were occurring between distributions, especially when there's a lot of over-plotting of dots. Probably would need some development to be able to select which quantiles to annotate in this way and setting distinct aesthetics, especially with >2 distributions.

I suspect the infrastructure to support such a feature might overlap with #229.