As you mentioned in other questions answer that related to RTL you said:
"Copy RTL CSS file from the HTML version from
to the Angular folder demo1/src/assets/sass/"
Are you planning to create rtl scss file because css file doesn't have variables and not flexible as scss.
We can try to integrate rtlcss plugin into the Angular webpack build.
We will consider using this approach to make the Angular use existing SCSS files, then convert them into RTL.