Change effective on 10 April 2017
Private-* Dynos used in Private Spaces are now accurately tracking Dyno Load. Prior to this fix, we were not tracking task PIDs for our load accounting, this means we were underreporting Dyno Load on apps that made use of threads. The performance of your applications have not changed, but you will notice an increase in the load reported to the Heroku Dashboard as the source data is now more accurate.
For more information, please see this Dev Center article.