Confirmed via BTS footage in the Target bonus material: when shooting the Mustafar scene, inner cloak was under the armor. So they must've fixed it in post. In BTS footage of other scenes, it is over, so they got clued in during production.
He is also indeed walking VERY fast toward Krennic in this footage, enough to give Wook a coronary.
They also show several stills of the costume on set, and it looks terrible under certain lighting conditions (i.e. not yet properly lit for a take). But the originals probably did, too. Lighting is everything!