+ // There are two ways you might write this method: (1) immediately merge
+ // resources from the bundle, or (2) store a reference to the bundle and
+ // merge resources later. Both have pros/cons. The implementation does #1.
+ //
+ // The upshot of #1 is *multi-region* support. For example, a bundle might
+ // add some JS to `html-header` and then add some HTML to `page-header`.
+ // Implementing this requires splitting the bundle (ie copying specific
+ // resources to their respective regions). The timing of `addBundle()` is
+ // favorable to splitting.
+ //
+ // The upshot of #2 would be *reduced timing sensitivity for downstream*:
+ // if party A wants to include some bundle, and party B wants to refine
+ // the same bundle, then it wouldn't matter if A or B executed first.
+ // This should make DX generally more forgiving. But we can't split until
+ // everyone has their shot at tweaking the bundle.
+ //
+ // In theory, you could have both characteristics if you figure the right
+ // time at which to perform a split. Or maybe you could have both by tracking
+ // more detailed references+events among the bundles/regions. I haven't
+ // seen a simple way to do get both.
+