[galaxy-dev] multiple cluster job runners?

I am looking at options to configure settings such as wall-time, memory, and number of cores etc. for each tool and wondering if this can be done using multiple cluster job runner configurations. Is it possible to define multiple cluster job runner configurations for each tool? In the universe_wsgi.ini file it is mentioned that individual per-tool job runners can be specified, however I don't see any example other than 'default_cluster_job_runner'. So is there any key-value syntax for defining it in the ini file? I appreciate any comments or suggestions regarding this issue. -- Thanks, Shantanu.