I was listening to an interview with Paul Rosolie (https://www.paulrosolie.com/) the other day and he mentioned a specific inflatable kayak that he uses in the Amazon rainforest. It's the Alpacka Raft Classic (https://www.alpackaraft.com/products/classic), and the smallest option weighs just 5.4 lbs and packs down to 16in x 6.5in when deflated! Granted, it's a pricey thing, as it starts at $990, but he loves it because it will easily fit into his pack so that he can traverse rivers whenever it becomes necessary. He also said that it's tough enough to handle some mild whitewater as well.
I don't have any actual experience of my own with it, but the reviews that I saw online were generally positive (with the caveat that this is one of the most expensive packable raft/kayaks on the market). There are larger / heavier duty varieties as well, which are even more expensive.
We've discussed these back on zs. The one you mention used to be one of the only options for backpacking a raft to cross rivers etc. Now there are other companies making these. And at least one that is more affordable. I just saw it. But don't recall the name.
One of the cast members on the show Mountain Men. Bought a piece of very remote land in Alaska. He hiked 60 miles into it. And had to use a pack raft to get across several rivers and streams. It worked very well. The only cumbersome part was the oars. Someone needs to invent a more compact or collapsible oar.
I'll see if I can find the cheaper one.
The cheaper one is the Klymit. Its 2.5lbs and $114.
KLYMIT LITEWATER DINGHY (LWD) Packraft, Inflatable Travel Kayak, Packs Small for Backpacking https://a.co/d/hlZ8WsZ
Heres a review of the main contender's.
https://gearjunkie.com/boats-water/packrafts