There's a note in CSS Grid (11.5 step 1) saying that these are handled as separate categories, but nothing in css-align says so. And also the Grid Container Baselines section (10.6 in Grid) also seems to imply that there is only one set of baselines. So we need to be clear about which is true.

Secondly, if they are in fact two different sets of baseline-aligned things, then which set is used when propagating the baseline up the box tree? E.g. a grid container with 50% items baseline content-aligned and baseline self-aligned, which is itself baseline (content- or self-) aligned in a parent grid or flexbox.

Proposal: Align the note and clarify css-align to match 10.6 in Grid: there is only one baseline that is shared across items in an alignment context, and both types of baseline alignment use it.