A question of to do it, size, or profile? You can do it, most crown we install is for 8' ceilings. It looks great. For 8' we recommend 4" or smaller crown widths. The profile depends on matching other decor or styles.

We added 4 inch to ceiling that high and like the look.

We have it too and it really provides a nice finished look. Lots of styles to choose from.

Yes of course.