Ok, tried this "perfoverlay.drawfps 1" - it showed the same frame rates like the origin overlay.
However, today i played 8 matches galactic assault (2x Tatooine, 2x Star killer base, 2x Yavin and 2x Thayd) on ultra settings and got always 70+fps and there was no stuttering at all.
Two days ago i had massive stuttering using the same setting (and even on lowest settings!!!) in the same game mode and maps (at least on Star killer base and Thayd i remember).
Changed nothing since sunday, just played on two different days.
In beta there were also no problems. Only thing i changed since beta is the nvidia driver because the game forced me to update from beta driver 385.69 to now a newer release, have installed 388.31 now.
Perhaps just server related lags causing the image to stutter? My internet connection runs with full 50Mbit down and 10Mbit upload with a latency mostly about 21ms. I never had problems in any other game in the last years.
Let's see what happens in the next days. I have an eye on it...