Considering that unique interaction basically means "one race specific line that replaces a skill check" having more of them doesn't really matter. Larian would need to increase the quality and effect of the race first, but we all know they won't do that.
As for the reason Dragonborn (and Half-Orcs) are absent in the first 2 acts, they finished them late in development and didn't go back to change existing content to add them, so Larian just dumped them all into the content they were working on, meaning Act 3.

Last edited by Ixal; 02/01/24 08:23 PM.