Lovely! So would there remain any downside to using anti-shock = 0 for everything? Would it be the only way in a future E-M1 II?
I shoot handheld most of the time, and I've definitely noticed shutter shock on my E-M1. You wouldn't notice it in casual use, but will notice it if you're scrutinizing the image for critical sharpness.
I haven't run into any downsides to using the 0s Anti-Shock settings. Once it's all tested, I may configure the E-M1 to do some auto-bracketing with 0s Anti-Shock as part of a custom mode.
The only potential issue is that it may add a slight delay to high-speed shooting, which may or may not influence your usage.
It's also not the most straight-forward thing to configure. You've got to menu-dive and deliberately select it as a shooting mode.