Has anybody's WMR ever updated during the day? I know the IRS says it only updates once a day, but is that really true?

That does seem to be true.  I have been obsessive and checked multiple times a day in the past, and never seen it change during the course of the day, usually it is at one status then the next morning it will change if it is updated when they send the overnight updates.

If you check more than 3 times daily, the system will lock you out.

Ive checked more than 3 times each day for the last few days, ( I know that's considered obsessive lol) and I have never been locked out.

I have never had it update during the day, only over night and some times it never updated. I can check wmr 5 times in 1 day after that it locks me out.