I've seen a few claims here recently that if you have a triggered auto-enter calc field, that you must set the trigger field to a different value in order to trigger a recalculation. Some people recommend using a Timestamp for the Trigger field this reason (Example)
In my testing this is never true, and I'm curious if anyone has a counterexample.
My experience has always been that the trigger field needs to be modified, but that modifying the the value to set it to its same original value still will get the job done to nudge the auto-enter calc to re-evaluate.
That said, in practice, I often to actually set the trigger field to a different value. In the past this was out of fear that some day what I had observed would change between version releases, and later just because I found it handy to store the current host timestamp in the trigger field.