Most engineered boards are sold, as fixed length that is to say the length of each board is the same. However nearly all engineered boards sold as fixed length still contain between 20-25% half or cut boards in each pack, often called starter boards. These can be installed within the bulk of the floor or as the name suggests used to start a row or as a cut to finish a row.
If you want a very uniform looking floor use the half boards as cuts, alternatively adding them into the bulk of the flooring creates a more random look.
Dry lay an area first, stand back and look at both options before you commit.