If your intension is to get into commercial aviation you need your multi-engine rating! I wouldn't procrastinate it for too long, the aviation industry can change fast and one never knows what the future will look like! If I'd be in your shoes I'd consider getting the CFI and get the CPL multi add-on while working as a CFI and buy the remaining hours to meet the regional requirements (which are usually around 50 hrs multi time). Since airlines prefer hiring pilots with CFI/teaching experience, I was told. Anyway good luck!