How to change contents of messages sent by Bitbucket's Slack integration?

[Enno]

In our team we try to minimize notification noise as much as possible. People should not feel overwhelmed by looking at a channels messages. That's why we want to display only the information needed in Slack messages sent by Bitbucket.

Here's a screenshot for clarification:

We don't want:

1. avatars (usernames are enough)
2. duplicated usernames
3. workspace info (it's always the same one)

Is this possible in any way?