Rewrite 'Tempus, Anyone?' so that Alt-Clark's secret identity as Superman isn't revealed on television (or at all), but still have it end with canon Lois returning to her Clark.

Now, go a step further. How does alt-Clark's life change, being able keep his Superman and Clark personas separate? Does he reconcile with Lana and live happily ever after with her? Does he go in search of his alt-Lois? Does he move on as a single Clark and search for love elsewhere? (cough, cough, alt-Mayson perhaps. ) What happens to Alt-Clark with this one change?

Keep in mind that whether or not he's out as Superman in his home dimension doesn't affect his coming to help canon dimension during the Doe arc.

Matchmaker Chronicles Volume 3 - The Lost Years
Matchmaker Chronicles Volume 4 - Despair to Hope
Matchmaker Chronicles Volume 5 - Hope Realized

Yes, Ken, that's true. I had forgotten that you had done this... well, your own take on a version of this theme in your Matchmaker Chronicles. If I recall, though, the revelation was undid outside the boundaries of the episode. (To keep it vague enough to avoid spoiling it for someone else.) I was looking for more along the lines of a rewrite of the episode itself to somehow foil Tempus's plans within the time frame of canon Lois's visit to alt-dimension.

I've been reading the excellent The Time Traveler's Wife by ML Thompson and recognize the premise.

Not sure it completely fits your criteria because "Tempus Anyone?" is part of the longer story and every detail isn't retold. The episode redo is told in flashbacks/memory and is towards the end. Some important details/situations have already changed by the time canon Lois shows up.

You picked one of my favorites. Again, it's another story, where Clark's actions in the past change what happens in the future. I don't recall Tempus's revelation about CK=SM being changed though. I thought Clark was still out as Superman at the end. (Won't say anymore if I haven't spoiled it already.)

What I really want is to have something change WHILE canon Lois is in Alt-Dimension, which makes it so she can leave without his secret identity being known.