Dereck: Yes, irregular flow of causality is type 4.
But being uninteractible because of being outside of causality is type 5.
And being uninteractible because of being outside of irregular causality is type 5.
DaReaperMan: That scan is completely insufficient. "There are no physical laws akin to those that dominate the mortal world", "Gravity, shape, space, and reason are in flux and mutable". That doesn't relate to causality at all, and does not indicate that a lack of causality is the reason for them being difficult to effect.
You haven't posted scans for other statements, but on the surface, they don't sound sufficient.
"Cause need not follow effect" pertains to Causality in that scan, but if you need a little more evidence...
"That is how events are viewed from the chronology of the material universe. In the Warp, things are different, for the Immaterium is not bound by linear time, and events do not occur in a strict sequence of cause then effect. As his rival gods reckon it, Slaanesh has always existed in the Warp, and has yet never existed at all." - Codex Chaos Daemons 6th ED
"Veslyin the Anchorite said that time has no meaning in the Sea of Souls. The warp can give glimpses of the past, the future and the present because within it they are all one. According to him when dealing with its denizens trying to attribute events to a timeframe in terms of past, present or future, is pointless – they must be addressed in terms of absolute actions." - Path of the Dark Eldar; this one above specifically meets the criteria of being invulnerable due to acausality
There are many other scans that pertain to none of the Materium's anything being present in the warp(supporting) or more type 4 for materium stuff, which are below. Correct me if I'm wrong on any of them lol
"All secrets might be known within the warp,’ said Mortarion. ‘It is timeless and eternal. Everything that happens here is reflected there endlessly. Every moment can be accessed, every lie heard, every broken promise relived. I have been deep within, far from Nurgle’s garden, into realms where secrets flock like corpse flies. I found many interesting things there. Do you know why He made us?" - Dark Imperium Plauge Wars
"With the departure of the Ark Mechanicus, the infected wound of the translation point snapped shut as the tortured skein of what mortals blissfully accepted as reality reasserted its dominance. The aftershocks of so brutal a manipulation of the laws governing the physical properties of the universe would echo throughout the past and the future, for such concepts as linear time simply did not exist in the warp." - Priests of Mars
"In order to regain its form, a Daemon must remain in a sort of purgatorial state within its master’s realm. Legend has it that a Daemon banished in this way cannot return for a thousand years and a day, though it is of course impossible to prove such a belief through study, and the concept of time itself is meaningless within the warp. Ultimately, how long the process takes depends upon the power of the individual Daemon, the favour of its deity, and the current balance of power available to the god in question." - Codex Chaos Daemons 8th ED
"It is a roiling, howling maelstorm of force and energy, utterly unpredictable and not subject to the rational laws and linear flow of time in the way that physical reality is." - Horus Heresy Book I: Betrayal, pg 16
"within its bounds, not even the concept of time holds any meaning. A champion may battle within this twisted realm for long months and discover upon his return to reality that only a single day, or an entire century, has passed. " -Warriors of Chaos 8th edition
"The Realm of Chaos is anathema to the laws of physics and ships that navigate its depths do so by taking a skin or bubble of 'reality' with them when they enter." - Codex: Chaos Daemons, pg 7
"At the centre of the Eye of Terror, the powers of the Warp run strongest, meaning the laws of space, time and reality do not apply. Some worlds are flat, floating planes spinning in the ether, others are surrounded by fireballs, while tiered worlds rise up, supported by intertwining pillars. No one can say how these realities exist, save that the pure power of Chaos washes over them and has made them so. Those worlds most steeped in chaotic energy are the abodes of Daemons, and are considered outlying colonies of the Warp, while the outermost planets upon the fringes of the Eye of Terror cling to more of the physical laws of the galaxy. In the centre, time not only does not flow, but also does not exist as a concept, save for when such trivialities might please the Dark Gods themselves." - Index Chaotica