It will never be safe imo. Your still essentially tricking the ecu into what figures it see's. A standalone is a far better option where the processor and memory actually see's the correct sensor values. Besides if you are looking to change away from the EMB, scrap the EMU, Dastek, PFC etc and just get a standalone, you can pick up a Haltech Sprint 500, Omex 600, DTA S40/S60 all for under a grand. Am sure you are more than competent to make your own field harness as well, unless you really want to change the loom for a Raychem spec.