[codecutter]

Thank you for your reply. I tried several options and finally found a setting.

I changed the setting for widget.non-native-theme.scrollbar.size.override from 1 to 50 and it increased size.

The initial value of 1 was confusing me because I kept thinking it is Boolean 1.

Posting a solution here in case someone else finds it useful.

[autoexec]

That is confusing... I'm not sure what the unit of measurement there even is. Something like pixels would be nice, but that can't be it with a default of 1!

about:config is invaluable, but better documentation on the options would really be nice.