Awesome pics - looks like a great trip. There's nothing like having a river all to yourselves!
HOWEVER... as a traditional whitewater enthusiast, I feel the need to issue a word of caution to the unannointed. Bear Trap at those flows is a handful. I would not want to experience any Class IV+ river at high spring flows without either the benefit of being accompanied by an experienced high water veteran of that river, or prior personal experience at a range of flows. Make that Class III+ in a packraft!
You wrote, "We later learned from hardcore kayakers that running the Bear Trap this time of year should be considered something between stupid and suicidal." You probably put this in for emphasis, but it doesn't really speak to the level of knowledge that I would want before embarking on such a trip. I suspect you and others in your group have considerable Madison experience, but that isn't stated in the article.
Perhaps I am more risk adverse that some... But I sense a general theme on BPL of trying to convince the world that UL backpacking is not really that extreme - and I agree it's not. Yet arguably packrafting Bear Trap at 4000 CFS is exactly that - extreme.
As for me, I have catarafted some moderately difficult stuff. Like May highwater runs on the MF Salmon, EFSF Salmon, Lochsa, etc. But I do it in the company of a very experienced group of catarafters with hundreds of Class V runs between them on the likes of the NF Payette, SF Salmon, Selway, etc.
Glad to see you in real PFD's at least! Keep safe and have fun. SYOTR.