We offer SubId Optimization through the Channel Summary report, where you have the option to bid up / down / or pause a subid.
To find your Channel Summary Report, click the advertiser name > click the campaign > change report to Channel Summary. Select one of your campaigns.
From there you will find a reports menu in the top center. It is defaulted to Daily Summary. Switch it to Channel Summary and there you can find performance broken down by sub id.
You can block/optimize based on sub ids in that report.