Board Thread:Episode Discussions/@comment-25319479-20180614110007/@comment-734582-20180614132143

Vladosaurus wrote: And why fight with your byakugan all the time when you have a rinnegan? He clearly can't spam it, or else he'd keep it active permanently like Momoshiki. Madara couldn't keep Rinnegan and Sharingan active at the same time either, so he simply kept it active once he needed it. Byakugan and Rinnegan similarly are mutually exclusive, so it's not like he can benefit from both. When kaguya naturally obtained those powers, they were integrated in such a way that she could use it all. Yet, Urashiki's powers are artificial. Vladosaurus wrote: Hold on, i didn`t realized that Urashiki`s left eye turned into rinnegan.I thought it was a forhead rinnegan. He closes his byakugan and when it opens, it's rinnegan. Elveonora wrote: Even after the glow effect, it looks reddish. The water is blue and so distorts the color a bit, but it looks red to me. I think it's something we may have to wait on before we get more confirmation.
 * his eye glows red only for a single frame

As to the other two points, Urashiki's power isn't naturally obtained, so the rules might be different here.