I will not even try to write about this but instead share the most well written technical page I have read in a long time http://deeson-online.co.uk/labs/multi-processing-part-1-how-make-drush-rush

He covers how to make a drush command run multiple processes in parallel depending on how many threads you give it. I show in the image below me starting up the command to run 9 behat tests sent to Saucelabs with 4 threads (could not go over that)

This reduced my testing time quite a bit for each cron job that runs these @critical tests.

Which is great. The next step will be to read up about the mtq where he integrates this in the DrupalQueue system!

now if only I had the Saucelabs account with unlimited threads!

Takes 10 seconds to start the jobs but this is "normal" for my behat to Saucelabs startup.