This way is a lot less efficient, but if you were to find out all the traits of the Sims you can deduce a general idea of what LTW they have (if they're not an original townie and you can't double check). Like if you have a Good, Workaholic, Light Sleeping, Grumpy, Artistic Sim (just listing off random traits at the top of my head) you'll likely run into the World Renowned Surgeon, or any artistic lifetime wish (as those are the 5 that tend to come up.
It's not even close to being accurate, but it might help for some of the bigger wishes (like avoiding Evil/Mean Spirited/Grumpy Sims to avoid the chance of redoing the Emperor of Evil Lifetime wish).
Also, if you have a genie in your household you can "Ensorcel" a sim for a few short hours which lets you view all of their traits and lifetime wish without permanently adding them to the household.
Those are the only tips I have for figuring out LTWs.