How to programmatically set the same flag for multiple transient-values?

Question

How can I programmatically set the same argument (e.g., --gpg-sign=abc123) for multiple transient-values? If I try the following, it seems that the value of adamliter/my-gpg-key-sign-git-arg does not get expanded.

(setq adamliter/my-gpg-key "abc123")
(setq adamliter/my-gpg-key-sign-git-arg (format "--gpg-sign=%s" adamliter/my-gpg-key))
(setq transient-values
      '(
        (magit-commit adamliter/my-gpg-key-sign-git-arg)
        (magit-fetch "--prune")
        (magit-merge adamliter/my-gpg-key-sign-git-arg)
        (magit-rebase "--autostash" adamliter/my-gpg-key-sign-git-arg)
        (magit-revert "--edit" adamliter/my-gpg-key-sign-git-arg)
        )
      )

After evaluating this, the value of transient-values is:

((magit-commit adamliter/my-gpg-key-sign-git-arg)
 (magit-fetch "--prune")
 (magit-merge adamliter/my-gpg-key-sign-git-arg)
 (magit-rebase "--autostash" adamliter/my-gpg-key-sign-git-arg)
 (magit-revert "--edit" adamliter/my-gpg-key-sign-git-arg))

But I would expect it to be:

((magit-commit "--gpg-sign=abc123")
 (magit-fetch "--prune")
 (magit-merge "--gpg-sign=abc123")
 (magit-rebase "--autostash" "--gpg-sign=abc123")
 (magit-revert "--edit" "--gpg-sign=abc123"))

Thanks in advance for the help. I'm not too familiar with Emacs Lisp, so assume I'm just making a simple mistake here.