login page font very thin MacOS Sierra on macbook pro 2015 15'' retina

After upgrading to Sierra the font looks blurry and I tweaked AppleFontSmoothing and font looks very thin, then I googled for a solution 

defaults write -g CGFontRenderingFontSmoothingDisabled -bool NO

and ticked 'Use LCD font smoothing' option in system settings, now everything looks normal again except the font of login menu:





as shown in pics the menu bar font looks thin before login but normal after login.

I've tried method in

All pages in Google Chrome are rendered with a very thin, bad looking serif font

but no luck, hope anyone could help thanks!
The issue is you're modifying two different global settings: AppleFontSmoothing and CGFontRenderingFontSmoothingDisabled. 

AppleFontSmoothing is an integer, represented from 0-4, whereas CGFontRenderingFontSmoothingDisabled is boolean. I'd recommend starting by deleting both, both as your user and globally (sudo) defaults delete -g AppleFontSmoothing; same with CGFontRenderingFontSmoothingDisabled.

The Menu Bar's process is called SystemUIServer. So you can restart the Menu Bar (see what your tweaks do) with killall SystemUIServer.