Symmetrix agent needs to be installed on a host that has gatekeepers attached to it, it does not have to be on the ECC server. It sounds like you have very limited experience with ECC, ECC is a monster but it's really old so if you are going to put any effort into getting the performance numbers i would spend the time to get Unisphere with Performance running.
How to Gather BTP file from Symmetrix.  We are using SMC to manage VMAX and ECC to analyze performance.  I am seeing WLA agent in the ECC and reports are till 2013. I don't know how to start the agent to get latest updates. 
How to Gather BTP file from Symmetrix