Would it be possible, to say, have a Global Starbase management screen?
The most efficient way I can see here is to be able to group starbases into a couple of categories, and then assign a build order to each category.
That would let me group all my Relic SBs together, my Relic + Mining, my Mining-only, my Econs, etc. And then do a custom build order for each group.
Maybe limit the number of groups (for UI purposes), but we should be able to assign starbases to a group and then use a build order queue for the whole group. Analogous to the Planetary Governer concept.