how do you patch LED lights on Element 2

In one of the Theatres I work in, in addition to a 96 Dimmer Rack, we run twenty-one of the 'ETC Source Four LED Series 2' and three 'ETC Relevé Spot Moving' lights, along with a Hazer and a Fog Machine using an ETC Element 2.  So, yes you can run both at the same time on the Element 2, no problem.

In one of the Theatres I work in, in addition to a 96 Dimmer Rack, we run twenty-one of the 'ETC Source Four LED Series 2' and three 'ETC Relevé Spot Moving' lights, along with a Hazer and a Fog Machine using an ETC Element 2.  So, yes you can run both at the same time on the Element 2, no problem.