It was nice that Lois knew, but I still contend that they should have stretched out her ignorance for a few more seasons. They also should have done more episodes about Lois and Clark dating and getting to know each other in a romantic sense. This has been discussed in previous threads, especially the "ATAI" episode thread.
Anyway... with regards to WHALLTA-related fics, there are a few.
Richard Frantz, Jr, has a very alt-world take on what happens in his
Lois's Secret . Not at all what you would think.
Lynn SM has an excellent fic where Lois thinks about Clark being Superman - how can she keep up? Definitely read her
Full Partners . Terry Leatherwood explores the same dynamic in his fine
An Unplayable Lie .
Lois needs time to think about marrying Clark, right? Some authors have explored this: Barb Pillsbury wrote
A Dickensian 4th , where Lois gets three ghostly visitors and is shown what might happen if she doesn't marry Clark. Rachel M. has Lois ponder Clark's question in
Didn't Take You Long .
There aren't too many other fanfics with the tag of "Episode-Related: WHALLTA" in the Archive Database. Perhaps this episode doesn't lend itself to as much "what-if" as other episodes like "Honeymoon in Metropolis" or "TOGOM".