Shortens the federal recovery window for certain disaster assistance repayments from three years to two years, restores a limited presidential waiver to allow use of some federal disaster assistance when a Governor requests it, creates a new limited waiver authority for FEMA to forgive some recoupments on defined "covered projects" (with a 5% cap on excess funds), and requires FEMA to set an "acceptable error ratio" for allocations so amounts within that tolerance may be used for eligible purposes. The bill adds these procedural and administrative rules to the Stafford Act to provide more flexibility, faster decisions, and clearer tolerances for financial adjustments after declared disasters or emergencies.