I think your idea is worth exploring. Personally, I feel variance exactly as cliveh described. Some days, I can tell the best contribution I will make in the darkroom is with a sponge and towel. Today is such a day. I hung the lightbox back on the wall behind the vacuum easel above the sink and drew the curtain. I basically have "no" creative energy tonight so I am doing cleanup. It's been a long week and I have to get out tomorrow for a day trip...
It doesn't matter what negative I might put in the carrier tonight, nothing good could come of it.
Now when I do turn on the faucet... I may predict Sunday or next Friday. That will be a different day.
Then I'll face the variance YOU described, where a resilient neg might make a good print immediately... or a questionable neg may or may not make the grade... But the creativity I put in, will be of a consistent character.
I'll tell you next week how it goes.