DevOps Automation: Add bitbucket pull request reviewers as option for "smart values"

I would like to have the assigned Bitbucket pull request code reviewers available for the new smart values for automation rules.

My use case: I have a custom field for "Reviewers" on Jira issues, which is a multi-user select.

I would like, when a pull request is created, to populate this custom field automatically with the reviewers assigned in bitbucket, and then be able to search and filter issues based on that.

I see, according to this page, that pull request title and url are already supported. https://support.atlassian.com/jira-software-cloud/docs/smart-values-development/

(The reason I need a custom field is because Jira only supports a single assignee and I don't want to change the assignee, I want to keep a history of who worked on this issue).