Remember our original, sketchy warp shields spent a pretty long time in the warp while we were out without the daemons figuring out a decisive counter. I have some doubt that the 'continuous security updates to defeat evolving threats' model is the right one vs. 'build a strong enough fortification for the assaults you face'.
Except maybe against Bongo specifically, but we can stop fighting Bongo whenever we want to.
And the time we spent in the warp then is proof that what causes investigations is daemons seeing Vita thinking about them. During all those thousands of years, she was barely thinking, so she was effectively invisible in the warp. The scratches that happened then were daemons bumping up against this shell by pure chance and investigating it, but they still didn't sense anything inside that enticed them.
That is potentially a defense, now that I think of it.
Yes, but that was still the nicer Warp before the Age of Strife and the Fall of Eldar. With the Chaos Gods still sleeping and no Slaanesh. Non-linear relation to time or not, at the very least their influence was massively weaker both in the Immaterium and in the Materium.
The Fall of the Eldar occurred over ten thousand years ago and ended the Eldar's supremacy in The Galaxy. Before the Fall, the Eldar were at the height of their empire and held sway over the vast majority of the galaxy; their worlds were paradises and full of peace and cultural achievement, and then it was all but destroyed. It is said that trillions of Eldar died in the cataclysm.[2]
The Age of Strife, also known as Old Night, was a destructive, anarchic and regressive time period prior to the forming of the Imperium. It followed the Dark Age of Technology, which by all accounts was an age of great prosperity. The Age of Strife began in M25[5] and ended in M30.[2]
You lead her down another short tunnel and reach the cargo hatch of your ship. She audibly gasps as she sees the rock and new metal transition to ancient alloy, visibly corroded by centuries. "By the Omnisiiah... how old is this?"
You reply quietly. "Fifteen thousand years."
So unfortunately no, our shielding is not tested even slightly in the current state of the Warp.
Daemons were an occasional problem that could be kept in check (mostly) by the Eldar gods. Not the near-omnipresent corruption it is the modern W40k setting. The warp before Vita escaped it and crash-landed on Denva was very different to what it is now. Kinda like comparing our RL oceans, but with giant eldritch monsters sleeping at its depths and occasionally their servants rising to snatch unsuspecting mortals...
To one that is all in a constant state of varying degrees of stormy weather, going up to "world-ending" and made out of radioactive/caustic/toxic/mutagenic. water. And the water also wants to eat your soul. And the eldritch monsters have awakened and sent their servants forth, and the sea is trashing full of them even on the surface as far as the eye can see.
I realize that metaphor was breaking down at the end, but I just want to emphasize that not taking current day warp travel seriously would be a bad idea. Which is why I want to keep updating the shields as time goes on, as we are bound to draw more and more attention, which might make us a priority target for various daemons.
And uh, lets hope that we won't draw even a passing glance from any of the actual Chaos Gods themselves for a
loooong time. Because I'm pretty sure that even a glancing attention from one of them would crush our current shielding. Luckily, we are also probably too small and insignificant at the moment for them to care that much. Yet that can change in the long-term, so again, my drive for constant updates to our shielding.
Not every single turn obviously, but I don't want us to ever fully stop and get complacent thinking that it is finally enough for the rest of the quest.