Lenore has clearly been researching something with antimagic properties. She clearly has ties to Shadovar and studied a Netherese enclave.
Indeed ...
THE ANTIMAGIC PROPERTIES OF SUSSUR TREE FLOWERS
By: L. De Hurst
For those knowing about Sussur Trees, their magical properties have always been a topic of debate; not only their ability to create an antimagic aura, which is complete enough that even those unattuned to the weave can feel its effect, but also - and most interestingly to those living in the World Above - the way its roots, bark, and flowers can be harnessed to make magic items. Rumors of such items are rare, but spread in settlements bordering the Underdark. Their actual existence, however, has never been confirmed by any of our clerics, or by any other reputable scholars. I hypothesised that these items are no mere legends, and indeed, in this treatise I will endeavour to explain how I myself created items with both antimagic properties, and ones using the magical absorption of Sussur Tree Flowers as a power source.
It just seems quite clear to me what was actualy main focus of her research ...
Not even single word about neither tadpole, netherese magic, metamophosis, or stasis of any kind ... only creating magical artefacts while using underdark materials. O_o
In her journal, Lenore writes that other people would rather kill her than converse with her. This is new. It's what has her writing in her journal, which she never would have imagined herself doing before. Something has had a massive impact on her life.
You mean "De Hurst's Diary" ?
As far as i know, she might aswell be talking about general unhospitality of Underdark ...
There is no great conspiracy, just the fact that she is operating on unfriendly teritory. O_o
Then she mentioned her actual work once again ... she was "called back to Baldur's Gate to confer with the other clerics of Mystra" ...
That can aswell be easily explained as she went to Baldur's Gate to show other clerics that using Sussur flowers she was actualy able to create Magical Artefacts ...
And yes, she is specificaly talking about "the ring" ... but since it seems that she never returned, i kinda doubt it was "the ring we can get from Bernard". :-/
Ignoring all of this because it's not explicitly spelled out is refusing to read between the lines and enjoy the mystery.
Its just matter of perspective ...
To me it seems that you are so focused on what might potentialy ben written between lines, that you forget to read what is actualy written on them.

I made a halfling and went back to the Arcane Tower to check the height.
The halfling was too short.
This is actualy valuable ... thanks for you to telling us.

It means that Lenore was probably not a Gnome ... so either gnome that is half eaten in Hooker Horrors nest, and that Deep Gnome from Duergar Camp that have the invisibility RING on herself ... is most likely not Lenore.

There is also the possibility that she was just a short human. I'm 138cm tall, and more or less human ^.^
I think this is great point.

After all Daddy Halsin is also hardly "typical" elf.

Ok Ragnarok. I can see you came to play.
Allways! :3
You know many people thinks that im just grumpy old man ... but i have heart of a young gnome. ^_^
In a jar ... on my desk.

Bernard's programming is able to recognize Lenore and react accordingly. Here's what any programmer without a death wish would code :
If kill_phrase and not(me) then kill
Indeed ... presuming that automatron is even able to work with conditioned algoritm.

If he is not ... its: kill_phrase > kill ... wich is exactly what we get.

So i dare to come to conclusion he was not able. :P :P :P
I'm not claiming she studied only anti-magic fields, just that it was part of the things she studied.
Well in that case we claim the same statement.

Just said differently.

What matters is that she definitely made items with antimagic properties.
Of wich we didnt find any ... except single mention in single book.
Is it possible that Lenore was cooperating with Blighted Willage blacksmith?
But we have found staff that allows us to CAST blessing empowered for casters, boots that allow us to CAST slow fall (at will, needed to say, there is no cost, nor any cooldown per rests), and ring that allows us to CAST light cantrip ... we have also found semi-sentient automatron, several automatic mechanized armors, and several magical turrets, that all react on anti-magic field from sussur flower ... and whole freaking tower, powered by magic squeezed out of sussur flower.
Im sory, but when i have all those things on one hand ... and single journal entry on other hand ...
I just cant force myself to believe that antimagic properties was actual focus of her reserach. :-/
It just seems too far fetched ... especialy since the very material she was studying have antimagic properties itself ... practialy all you need to do is wear Sussur flower in your pocket and you just created any meele weapon with antimagic field property, as long as you remain in the Underdark ofc.

You're correct to point out there's no direct proof Lenore made Omeluum's brew. But imagine you found an abandoned kitchen with a bunch of italian cookbooks, flour, tomato sauce and mozarella. It would be safe to assume the chef tried to make a pizza or two, even if the kitchen also contained pickles and strawberries.
That is exactly the thing ... concidering how many things is there to support theory that she was brewing Omeluum potion, and how many other stuff is all over the place ...
It seems to me like, to use your own example, as if you say:
Imagine you found an abandoned kitchen with a bunch of italian cookbooks, flour, tomato sauce and mozarella ... the kitchen also contained pickles and strawberries.
And then come to conclusion that since there was strawberries she was clearly making a cake!

I mean cone on ... even if you decide to ignore things we can find in the barrels, there is at least double amount of different kind of crystals, there is at least double amount of mentioning effects of sussur flowers ... than litteraly two or three mushrooms of this specific kind.

And if you include things we will find in the barrels ... there is sudently MUCH MUCH more other things.

I could, yeah... Especially if I found a book close by called "The psychotropic properties of poppies", and the nextdoor neighbors told me, "if you're looking for poppies, go there. That guy definitely has poppies."
Yeah he do have poppies (i love the word by the way

) ...
Aswell as aproximately 10 other flowers ... crystals ... mushrooms (not halucinogenic tho

) ... and other stuff.

I would also like to point out possibility that she created that "killme" comand after experimenting with Tongue of Madness ... and had a little accident.

Yeah, that's a good point. I kind of pictured Lenore drinking that Tongue of Madness potion every day for a long time. Maybe that slowly drove her insane.
Nah, it was just a joke ...
BTW ... just another idea ...
Lenore is suppose to be Cleric, right?
We know from the letter that she had unhealthy relationship with Bulette, concidering it her pet instead of wild and dangerous monstrosity, right?
We also know that there is Medium Armor chestpiece in the Bulette belly, right? :-/
What if ... :-/