Upload your entries file and use the One Group Per Contest template. Each contest gets its own lineup group, filled with the number of lineups you entered and ranked for that contest.
To run a build specifically intended for one, or a subset of your contests, simply delete the groups that you don’t want to build for in this build.
Then, set any rules required for this build, build lineups, and adjust exposures accordingly.
When you save, only the contests attached to lineup groups in this build will be filled with lineups. You can then create as many new builds as needed to fill out your other contests, and when done, you can download your completed entry files with the lineups assembled from each build.
Note that lineup groups can’t leave entries in a contest unfilled. For example, if your contest has 20 entries and your group is only set to 15 lineups, it will duplicate 5 of those lineups to reach the required 20. It can not leave those other 5 blank.