Our team sees benefit to doing both, and making a deliberate effort to place energy-items into either the "audit" or "Cx" category (so we don't duplicate too much). The local utility offers incentives based on doing Cx, so the fact that we are doing both Level II and Cx is less of a burden to us.
The LEED-Letter-template for EA2.1 won't allow both Cx and Level II options (you must pick one). For ours, we plan to pick the Level II. So, in order to get credit for EA2.3, we will have to explain in narrative on the LEED-Letter-template for EA2.3 that we are actualy doing a combined retro-Cx + on-going-Cx, with appropriate uploads. Has anyone done this? Did GBCI award the points for both credits EA2.1 and EA2.3? Any advice? Thank you.