I agree that {{onCoordinates()...ofCoordinates() }} is a bit confusing. I propose to change

{code:title=SpatialContext.java|borderStyle=solid}}
public interface SpatialContext extends QueryCustomization<SpatialContext> {
/**

• Used to create Spatial Queries on the default coordinates of
• an entity. This is the one to use when {@link org.hibernate.search.annotations.Spatial} is being used
  * without defining a custom value for {@link org.hibernate.search.annotations.Spatial#name()}.
  *
  * @return {@code SpatialMatchingContext} instance for continuation
  */
  SpatialMatchingContext onDefaultCoordinates();
  
  /**
  * An entity can have multiple {@link org.hibernate.search.annotations.Spatial}

  annotations defining

• different sets of coordinates.
• Each non-default Spatial instance has a name to identify it,
• use this method to pick one of these non-default coordinate fields.
  *
• @param field The name of the set of coordinates to target for the query
  *
• @return {@code SpatialMatchingContext} instance for continuation
  */
  SpatialMatchingContext onCoordinates(String field);
  }
  
  
  to
  
  {code:title=SpatialContext.java|borderStyle=solid}}
  public interface SpatialContext extends QueryCustomization<SpatialContext>, SpatialMatchingContext {
  /**
  * Used to select the spatial field/coordinates used for this query. If not specified, the default field
  * ({@link org.hibernate.search.annotations.Spatial#COORDINATES_DEFAULT_FIELD}) is used.
  *
  * <p>
  * Note: An entity can have multiple {@link org.hibernate.search.annotations.Spatial} annotations defining
  * different sets of coordinates. Each non-default {@code Spatial} instance has a name to identify it. Use this method
  * to specify the targeted coordinate field.
  * </p>
  *
  * @param fieldName The name of the set of coordinates to target for the query
  *
  * @return {@code SpatialMatchingContext}

  instance for continuation
  */
  SpatialMatchingContext againstField(String fieldName);
  }

Basically dropping onDefaultCoordinates and renaming onCoordinates to againstField.