sort by channel not used to visualize?

I have a dataset sorted by a column, lets say rate. I then create a stacked bar chart using a different column, lets say value.
I want a stacked bar chart on value but sorted by rate. Even though my data is already sorted by rate, when i do the following it orders the y domain alphabetically:

Plot.barX(data, { x: "value", y: "name", fill: "type" })

if I try to use sort: { y: "x", reverse: true, limit: 20 } I can't figure out how to get it to sort by my rate column instead.

I'm able to do a work around by explicitly setting the y domain to the sorted order of names I want, but it feels like i might be missing something?

Start with the Plot.barX example and the sort option described in the issue, then trace how the y domain is derived when x, y, and fill are supplied. Compare the current alphabetical ordering with the requested ordering by the separate rate column; done means a stacked value chart can use rate for y ordering without manually specifying the y domain.