If I follow the Create New Board wizard it will only offer nRF54L15 from the 54L series SoC (I want 54L10)
The others are included in the SDK, and if for example I make a new application & build configuration with the 54L15DK as a target I have the option of -05 -10 -15.
For the moment I can just use the 54L15DK build configuration, but very shortly I want to be able to define my own boards.