Copy postgis layer from S3 to Heroku

I have a dump of a postgis layer (layer.dump), which I am trying to add to my heroku database (mydatabase). The postgis layer is stored on S3 (https://s3.amazonaws.com/layer.dump) . I would like to add the layer to to the heroku database and previously used heroku pgbackups:restore DATABASE 'https://s3.amazonaws.com/layer.dump '. However, the new heroku pg:backups restore 'https://s3.amazonaws.com/layer.dump ' DATABASE deletes all data from the target database before restoring the backup (https://devcenter.heroku.com/articles/heroku-postgres-backups) . Is there still a way to only restore a single table and leave the remaining tables in the database untouched?