Having had an Olympus camera for the last 8 years I'm totally used to firmware updates ! First thing I do when I get a new camera (or lens) is check the firmware.
As to listing bug fixes - I have a Tesla and that gets a software update about every 2-3 weeks. Every single release introduces new bugs that are usually fixed in later releases - but the release notes NEVER say what's fixed.
I had an EM5 for 6 years. I never updated the firmware.
It worked fine, and perhaps being used to the software I use for work, each update usually brings some new problems.
Still this is new for me, a lens that requires the cameras software to be updated.
But it is a whole lot better than when I mated a Panasonic 12-35 2.8 (the only 2.8 zoom available at the time) to my EM5. The only way to avoid horrible green CA effects was to shoot Raw in DXO which proved to be the only software capable of removing the CA's automatically.
Or the 16mm AF Nikon Fisheye that I bought too yesterday. I plonked this "ancient" lens on my D800 (which I keep for "old" AF lenses) and it worked perfectly.