Ivar stopped by to ask if there was a way to form CDF metadata such that the x values will have min and max defined. I thought that we did this for LANL on RBSP, but I wasn't able to trigger it easily.
I did find that LanlNNRebinner does look for BIN_PLUS and BIN_MINUS metadata, and I was able to write a script to generate this. Exporting this data as CDF and reading it back in did not work. See https://github.com/autoplot/dev/blob/master/bugs/sf/2859/testbins.jy
Here's an example of a URI with error bars in Y: vap+cdaweb:ds=RBSPA_REL04_ECT-MAGEIS-L3&filter=RBSP&id=FEDU_ERROR&timerange=2019-10-13