In June I miss-timed it.I concur that the battery life with the 12-100 on my Pen F (same battery as the E-M1) is shorter than the battery life with the 12-100 on my E-M1 II. Luckily, my usage of the Pen F is not as demanding as using the E-M1 II, so not as noticeable.
At a graduation, the battery went to "empty" just before the tassle turn, so I missed it.
Next year, I'm bringing the EM1-mk2.
I brought the EM1-mk1, because I did not have enough shutter time on the mk2, to trust it on a critical shoot.
But I got burned anyway.