Panasonic bakes the correction into the RAW files? I doubt that. It’s a switch you can turn ON or OFF. I just tested it with S5 and S1R, one lens with and the other without DxO profile and I don’t see PL acting different. but the test was rather quick and dirty. However, I could imagine: if there’s an effect like a halo, it will be sooner visible on µ 4/3: the sensor is smaller, FL’s are shorter, therefore more prone to vignetting.
Out of interest: The vignetting I can alter in the “creative vignetting” board? Anywhere else? I just was searching for vignetting (or better “brightness fall-off”) in the lens correction board, but could not find anything there.