I think tariffs are generally applied based on date of customs arrival, not time of order - discussion on wine imports who order months+ in advance as well as some small businesses getting hit unexpectedly on long-ordered goods, plus my own industry that has a several month lead time on orders and some bills we have received. I’m less familiar with that mechanic but I don’t know that placing the order before that time will help you if it has to ship from overseas.

And 85% of medical isotopes come from Canada!

That does get audited - customs officials do have a look at a lot, and frequently check products against stated claims.

At least this is my experience with my own company’s cross border business - labeling, valuation, documentation of sales and invoices, etc, all matter. We’ve had shipments to the US stopped and held before over what you’d consider minor issues with labeling or newer guys at the ship desk leaving i’s undotted or t’s uncrossed. I’ve had some panicked calls about costing and valuation documentation in big shipments. There were some loopholes to a few rules, but they were small and because these tariffs apply to pretty much everything from any given country, I have a hard time imagining there would be major work arounds for this.

Smaller drop-shippers with more discreet packaging might be able to get away with reducing their numbers - or at least rolling the dice on not getting checked - but for large commercial shipments, absolutely not.