@BBC_News_Labs May I point out that in order to be successful on Mastodon, you're going to need to *interact* with people. The (new?) old days of posting into a void on Twitter don't work very well here.
If your experiment is going to succeed, I think you're going to need to try differing levels of engaging with your audience.
Also, there's already a bot account that's reposting BBC News articles that a lot of people follow. That might interfere with your findings if you don't address it.