BuddyPress.org

There are lots of CSS hooks so you can customize the look of your messages pages. It would be easiest to just use some creative theming and create the effect. You could hide most profile information/avatar using CSS.

Or you could also try creating a custom page template using the private messages loop and adjust the parameters to suit your needs.

https://codex.buddypress.org/developer-docs/custom-buddypress-loops/the-private-messages-loop-bp_has_message_threads/