One important point to bear in mind is that although European life jackets are identical in design and safety, National Park Service rangers often do not accept them unless they bear the specific US approval label. This is because in the US, PFDs must carry a certified approval from the US Coast Guard (USCG), and this visible label is usually the official verification that the life jacket meets the buoyancy and safety requirements of that country.
The USCG certification may appear as a label on the life jacket with the approval number and, under the latest system, buoyancy level icons (e.g. Level 70, traditional equivalent of the old Type III for kayaking/whitewater) indicating its suitability for recreational activities and inland water navigation.
If you bring a PFD purchased in Europe that only has CE certification (ISO 12402) and does not clearly show that it is approved for use in the US, rangers may refuse to allow its mandatory use at certain checkpoints, regardless of whether its actual performance is equal to or superior. Some groups have explained to us that what some people do if they want to wear their own non-American life jacket is to show the Ceiba one at the checkpoint when entering the Grand Canyon and then put on their own.
Thanks to the fact that Ceiba includes PFDs in the Whole Shabang!, we don't have to worry about this: they ensure that the life jackets they carry are suitable for white water and comply with the necessary certifications to navigate and pass NPS inspections without any issues. For our part, we simply verify the size, adjustments, and that everything is in perfect condition before putting them into use.
Just in case, one thing I have packed is a cowtail with a carabiner (I'm sure I'll catch a Packraft or two that has lost its packrafter 😜), as well as tape for the cowtail.
I have also added a whistle, which always comes in handy (plus the one I carry has a built-in thermometer, which is ideal for knowing how cold it's going to get), and a knife (not ideal for kayaking because I lost it in the Lumi i Shales River in Albania), but a carabiner-style substitute for canyoning.