Can I use the free (<10 users) version of Jira with an existing >10 user Bitbucket account?

[JaredHonda]

To give some context, we currently use a third-party tool for project and development tracking. It works well, but we want to see if it's worth it from a workflow standpoint to instead use Jira + Confluence (and potentially other Atlassian products) in pursuit of a more unified ecosystem.

We have had a Standard Bitbucket account for a few years now but we don't want to commit to paying for Jira or Confluence until we have been able to try it out with our current projects.

I am an admin in our workspace and I would be the only person trialing Jira/Confluence for now so we wouldn't want to put all our BB users on Jira/Confluence during the evaluation period. The signup page isn't clear about how it would work billing-wise if we link the accounts together.

The page is here: https://www.atlassian.com/software/jira/free

So, can I sign up to use the free (less than 10 users) version of Jira + Confluence to use with our existing Standard Bitbucket account? Or does my use of the free version not work if BB is already being paid for?

Thank you in advance!