The top of your Loan Estimate's cost table — origination charges, the points you agreed to, the lender's own processing and underwriting fees — is held to the strictest standard the rules have: it cannot increase at closing. Not by a rounding error, not by a "final numbers" adjustment. The number on the form is the number, which is why it is also the number worth comparing between lenders.
The escape hatch is called a changed circumstance, and it is narrower than it sounds: a genuinely new fact — an appraisal coming in different, a credit score revision, you changing the loan itself — documented on a revised Loan Estimate issued within three business days of the lender learning it. "We re-checked our pricing" is not a changed circumstance. A revised estimate that arrives late, or that cites nothing, does not reset the tolerance.
What to do with this
Keep every Loan Estimate you are issued, including revisions — the tolerance comparison runs against the right one, and which one is "right" depends on those changed-circumstance rules. When the Closing Disclosure arrives three days before closing, the comparison against section A takes minutes and is the highest-yield reading of the whole transaction: a violation there is money the lender owes you back, by rule rather than by negotiation.