Why a package trigger another's download even when I have built-in in the other's recipe?

[WorldsEndless]

Why does elfeed-org always clone a copy of org even when my org recipe has straight (:type built-in)? After an annoying bit of bisection I found that without elfeed-org, the built-in version is respected and a straight repo is NOT cloned. With elfeed-org, however, I get an org repo and m-x org-version telling me "mixed version." May any package trigger a parent package build, or is there something peculiar about elfeed-org? Is there anything I can do to get elfeed-org to stop triggering the org repo?

[progfolio]

Are you able to reproduce the issue via straight-bug-report?
That would help narrow down the issue. Thanks.