How can I speed up development builds while developing a linked package? (Ember/Broccoli)

My Broccoli builds take up a LOT of time. ~30 seconds to build every time I change a line of js (I mean the incremental re-builds with dev server running, NOT a complete build).

Here's my situation. I have project A which is an ember addon to project B which I npm link in. As I'm developing project A, I am running ember server on project B.

EVERY SINGLE TIME that I make a change to a line of javascript in project A and rebuild, I see that the following files change in project B:

B/dist/assets/vendor.css
B/dist/assets/vendor.js
B/dist/assets/vendor.map
B/dist/assets/B.css
B/dist/assets/B.css.map

My concern is that, because I'm developing a linked package, my broccoli configuration is such that the entire node_modules is recombined into those vendor files.

Is there a way for me to configure ember/broccoli to use a separate file to compile A into and segregate it from the rest of vendor.js? B/dist/assets/A.min.css and B/dist/assets/A.min.js for example?

...or I'm a guessing at the cause of the problem incorrectly?

Thank you so much for your help in advance!