css scope not work when set inheritAttrs=false

[tangjinzhou]

Version

3.0.0-rc.9

Reproduction link

https://codesandbox.io/s/elegant-moore-rfyck?file=/src/B.vue

Steps to reproduce

1、use nest component, root dom at deep child
2、set inheritAttrs = false，css scope not work

we can use v-bind="$attrs", but maybe we can have simple method

What is expected?

css scope work

What is actually happening?

css scope not work