Any luck with manual focus?

Bird-in-branch is one of those cases when you'll need to go MF even with a native MFT lens.

Using the G1, the EVF and MF assist really help a lot. But then composition is typically not your priority, due to the heavy cropping that will almost always follow anyway...

For moving subjects, I guess that MF is always a special challenge. MF assist often seems "too much" to me then (can't track because the field of view is too narrow). I had some amount of success by pre-focussing on a chosen point that was supposedly at the right distance - but this is more technique than platform, indeed.

Here is a MF picture of a moderately mobile bird: