@Necroes Actually, i think the reason Zuriel might know is that Zuriel remembers how orks should be like, what sort of presence they have in the warp.
Not that he has met orks himself, but that's not important.
So knowing that orks should have a distinctively orky presence and sensing Urgrugg, Zuriel will find that Urgrugg is more akin to a chaos sorcerer. Which could have Zuriel speculating, but not actually knowing if he's cut off from the gestalt field or not.
And i've never claimed we cannot travel through the warp.
I just don't want to be a piece of cake in the annual meeting of the society of people with severe over-eating disorder and comfort eating compulsive disorder.
Grey knights have MASSIVE protection against deamons, and could stay stranded in the warp for years without their protection failing.
Warp spiders are just stupid, "Chance to get horribly eaten by deamons and my soul damned for eternity? Meh, sounds alright. I'll do it."
I don't feel stupid, hence why i want to have a ship with already finished protective systems. Be they rune shielding or a gellar field or a wraithbone hull (which actually does the same job, among others).
Since we do not have time to fix such systems, inscribing runes is just that. Painstakingly marking the ship surface with runes. The smallest ones are over a kilometer long so we're talking weeks to scribe it.
And we could probably fake it with a ritual, but that is so sketchy i don't want to do it. And we'd need to feed the ritual somehow.
Not to mention opening a rift into the warp, warp engines are a thing and require massive amounts of energy.
Luckily we could hope for a warp generator implosion and run into the ensuing rift, no problem. Well, apart from all the problems the warp mean.
Also, pop in for a minute means very little in the warp.
Sure, we could get out of the system, we'll probably just travel to the other side of the battle. Being the warp we could be stuck for millennia for that minute, or we could as well end up at Sol.
The most probable outcome though is that we will pop into the warp, with no navigator to guide us we will be lost and while an ork faking navigational duty is better than nothing, i wouldn't bet on this plan.