We use Insite Manifest and have for years. It’s been a reliable solution for us. We have integrated with UPS/FedEx/USPS and use international options for each. The integration with carriers is works great. The international forms are automated and simple for our shipping teams (Nafta, Customs Commercial Invoices ect).
You may need to setup international codes on parts. I have seen some users assign each code to thr product groups and automate on new part entry with a BPM.
Haven’t used Agile ship, so I cannot comment.
Let me know if I can help with anything.
Bryan DeRuvo