Sierra certainly has its share of bugs. The frequent freezing that Macbook Pro has been experiencing is a bigger problem than erratic keyboard behavior. Do you have a maintenance release of KM planned any time soon?
Maybe, but not to resolve any kind of Sierra issue like you are describing.
. . . and lack of compatibility with some applications, or design changes that affect how it behaves with apps.
That's why I almost always wait at least several months (sometimes up to a year) after a release before I install major updates to any OS.
Using broken stuff keeps me attuned to what users really need and equips me to give advice like āwait a few months before upgradingā. I use the macs primarily because the way they render text on the screen is easier for me to read. When I need reliability I use windows. I have a variety of machines available (6 PCs, 5 Macs, 3 iPads and an Android tablet) and a bunch of VMs with linux and older versions of windows (going back to windows 98) so Iām rarely without a way to get something done.
Mac screens not withstanding, I considered Mac to be essentially unusable until they enabled resizing windows some place beside the right lower corner and the Mac laptops only when I was able to remap a key (like F12) to do forward deletes. My day ends up with iPad in the morning, windows in the afternoon and the Mac in the evening and, if I need access to an OS specific function I just remote to one of the other machines using VNC or RDC.
As you can see, getting any particular key remapped is only essential to prevent annoyance, so I can wait while Sierra gets sorted out.
We have been able to resize Mac windows from any corner for a long time now (years). I think maybe since Mt. Lion.
That's funny! 
I have used both Windows and Macs for many years (decades) now, and find the Macs are far, far more stable than Windows. Like most Windows users, I have suffered many "blue screens of death".
But then I don't load up my Mac with a lot of apps/utilities/system changes that try to make the macOS do stuff it doesn't really support. I find that with tools like Keyboard Maestro, LaunchBar, AppleScript/JXA, Typinator, etc I can highly automate my Mac and still have a very stable OS.
I've been running Keyboard Maestro 7+ on macOS 10.11+ (El Capitan) for about a year now, and it works really great. macOS Sierra does not provide me with any compelling reasons to update, so, as usual, I'll wait a few months until all the kinks are worked out, and all of my essential apps are fully supported.
To each his own. There is always a price for being on the bleeding edge. 
Of course, but that was after my Mac classic and my Mac II FX drove me nuts.
In reading though this thread I didn't see any mention of this setting in the System Keyboard Prefs:
It should be checked if you want to use bare Function-Keys for keyboard shortcuts.
-Chris
itās checked
Have you tried to boot in Safe Mode? (Hold down Shift after the startup sound.)
Amongst other things Save Mode disables certain kernel extensions and all Login Items, and it deletes kernel and system caches.
While in Safe Mode you have to launch KM Engine manually: Open KM Editor > File > Launch Engine.
Then try if something has changed. Then reboot in normal mode and try again.
Thanks, Iāll give it a try