I assumed the Speed GR descriptions were specific to the Speed GR setup and not the Neph Rifts one. But even if those descriptions were also included in the Neph Rifts section, I don’t understand how that justifies the Neph Rift variant because:
I’m not sure how this is relevant? The Neph Rift variant only drops Jesseth but does NOT drop ORotZ.
My guess is that in the Speed GR version, they can drop ORotZ because of Captain Crimson, but the Neph Rift variant doesn’t have Captain Crimson, hence the need for ORotZ and a resource spender for it, and I don’t know why they still use CS in that non-Jesseth case because BS or DN are more efficient.
This only explains why Jesseth is replaced with In-geom but not why you would use CS with ORotZ instead of BS or DN with ORotZ for the non-Jesseth case. Unless perhaps the the Neph Rift variant is incorrect?