I really did not think running tests is not so much more complicated that before. It's just two commands. We could create scripts in package.json to make it easier.
Please keep in mind that only one person is working on Selenium framework. Because of that we (my team, not royal "we") have decided to support only two environments. MediaWiki-Vagrant and Jenkins. The assumption is that if people prefer a custom environment they will be experienced enough to be able to make adjustments to Selenium framework to make it work for their environment.