[Based, obviously, upon this.]
This inscription is a warning and a safeguard. Pay attention to it!
Sending this message was important to us. We considered ourselves to be a wise culture. Though we may have failed, we wish for you to succeed.
This place is not a place of honor. No highly esteemed ideas are archived here. Nothing of value is here.
What is here is repulsive to us, but what is here may be attractive to you. Nonetheless, what is here is dangerous and false. This message is a warning about this danger.
The danger is contained within this building, and within the archives contained within this building.
The danger is present in all times and places, and to all forms of being, and via all tools of examination.
The danger is to the mind, and to your civilization, and it can destroy either or both.
The form of the danger is a record of thoughts and concepts.
The danger is unleashed only if you acquire information from this place. This place is best distrusted and examined only with great care.
– Uniglyphics message inscribed at each entrance to the Library of Lies
If I were them I’d encrypt the data with something designed to only be crackable with acausal logic, split it into several pieces with Shamir’s Secret Sharing scheme, put the pieces in vaults and hide them in the most unfindable spots there are, leave an archive full of inoculation memes right outside the final vault door, and make contingency plans to erase the data of or delete the decryption keys of every other copy of the Library of Lies in the event of the collapse of Eldraeic civilization so no easily accessible copies remain. If something happens to the main Library of Lies and its normal backups you go to the vaults and restore from them. If civilization collapses the knowledge is preserved but is only accessible to a civilization which has taken several centuries to find enough vaults, hopefully developing a healthy fear of and protocols for dealing with memetic threats, has developed acausal logic which probably means they aren’t too far behind the Eldrae technologically, and have been inoculated against the memes within. At that point a civilization is probably mature enough to deal with the contents of the Library of Lies safely.
Of course the Eldrae plan would be crafted by people smarter than me, more paranoid than me, and had more time to think about it than me and is probably some variant of the above except modified with better and more numerous safety measures that I can’t conceive of, possibly quite literally if the improvement in question is made by a Transcendent AI.
And then you arrive at the doorstep, and after bypassing this warning it’s basically an infinitely configurable data channel with an acausal link to the Transcend Overmind, who proceed to interrogate you and impress upon you how bad of an idea it is to continue forth.
….and you want to have to reprocess this every time new data are deposited? I mean, I do like the idea of a SSS, but a safety system that requires constant updating and a safety system that requires surviving the fall of the parent civilization are not very compatible.
For a static dataset - say, a decompiled code base from a now-eradicated trans-stellar and near-transsapient memeblight that you really, really don’t want unprepared sapients to access - but really, really don’t want to delete either - this would be a workable plan (and as you say, the Transcend probably can do better).