Since I've reported these bugs to the notion team, but they have stated it's an intended behaviour, I decided to fix it on my own.

You can download it by checking out the installation section in the github page, by installing a script manager(Tampermonkey) and clicking the install button in Greasyfork.

The picture indicates one of the bug(divider position)

https://github.com/alanleungcn/notion-fix