While thinking about my response, it occurred to me that only contributions that you made to the HSA outside of your employer appear on line 25 - your payroll deductions have already been removed from your wages, so there is no need for a double entry.
So there is less of a reason for the IRS to send you that letter quickly - it won't be until they notice that you had a code W on your W-2 or notice that you were issued a 1099-SA, which might not be for months.
In either case, I think you should do the same thing (wait for the letter and then amend in 3-4 weeks); I am just thinking that it is less likely that you will get the letter.
You want to correct this one way or the other, BEFORE April 18th.
