Hana, this is really a question about which door has which clock, and the real issue here is that most desks see only one door. First, the protest is the administrative door: it challenges something Customs decided, and it closes at 180 days. Second, the court's residual jurisdiction is a different door altogether. The trade court has held that assessing IEEPA duties at liquidation was not a Customs decision at all, so no protest was ever needed to reach it, and the complaint itself is what preserves the entry. That door runs on a two-year clock, counted conservatively from the day the tariff was imposed, not from liquidation. Third, in July the court ordered reliquidation of finally liquidated entries, but only for importers who had actually filed. So yes, a complaint reaches past the 180 days; the portal on its own does not.
For Tomás, cross 1520(c) off the list: it was repealed in 2004. What this client should have had all along is a liquidation calendar in the compliance manual, so nobody learns a deadline from a refusal letter.