The Emperor could easily close those tax loopholes

Were they not closed?

You could tell by how Grand Admiral Thrawn

Thrawn has daddy issues & just likes to be choked, it's a known "secret", and it's kinda super weird.

Not to mention how he kept his position when the full blueprints were published on War Thunder forums.
(Some of the constriction crew literally used the forum blueprints to built it.)