This is roughly what I’m expecting for conditions. The whole point of the early start is to get low flow.
We launched Marsh Creek in early May (10th or 12th) one year with flow on the Middle Fork at about 3.2 feet or around 1,500 cfs at the gauge near the Middle Fork Lodge. Which has definitely not seen 9 feet of flow this winter. There is not enough unfrozen water in the entire drainage to make a 9 foot surge this time of year. A kayaker on the trip sent me a picture at one point looking downstream at several boats. Then he asks if I know what was unique about the photo. I couldn't see it. He then says 'every single boat (some cats) in the picture is stuck.' I, of course, was stuck as well. I probably have close to forty low water trips on the Middle Fork. By this I mean under 1,000 cfs or 2 feet on the gauge, with 15 or so of those being under 700 cfs (1.65 feet) but I still had my ass kicked by Marsh Creek at 3.2.
Now I am not a safety nazi or even close. At low water I rarely wear a PFD ( and I don't need to hear anyone's shit on this...I don't care what you think), I don't wear a helmet as a rule unless paddle boating and I advocate for adventuring all the time. If you have not seen this stretch of water I am advising you not to go. There are multiple spots with braided channels, there are also several significant avalanche slide paths that consistently make it to the river. I have floated past 20 foot tall slide debris paths with 80 foot trees sticking out like a mutant pincushion.
We have had some big avalanches up here this year too. Weak faceted snow layers from early are continuing to release very large slides all over central Idaho. I would be more surprised if you didn't have some snow tunnels to deal with than if you did.
But hey I have only done Marsh about 8 times at flows from 3.2 to 7 feet....and I think this is a bad idea. But I have also had the USFS pull up and ask us to help look for the body of someone who flipped on a log jam so I am a little less nonchalant about the dangers than someone who has never seen it. Put a little somber side on our kayaking that day.
Also your video of 'what you expect' - the flow is about 7 feet which I think is about the easiest level for Dagger. Lots more steepness to the drops at lower flows and lots more sharp rocks. So I would expect something much different looking than that.
Here is another cautionary tale of Marsh Creek. These guys had multiple Marsh Creek trips and were trying to follow good safety protocols. Marsh Creek don't care. I met them at Boundary Creek. Their trip was over. Five shredded boats and one broken ankle I believe out of their trip.
The primary advocate for the preservation and protection of whitewater rivers throughout the United States and connects the interests of human-powered recreational river users with ecological and science-based data to achieve goals within our mission.
www.americanwhitewater.org
Then there is this (pic below): Below the main drop at Dagger and very hard to see from above or below at river level. We had to climb out on a cliff and look almost straight down to see it. Photo taken May 17th last year the day after the road was opened.
The picture below also shows the log in the right line (that showed in the earlier picture from August in this thread) so it is very doubtful that the x logs above were blown out by higher water. But maybe you can limbo under them. Someone said a couple of kayakers had run it and flipped over to miss the logs then rolled up, but not sure what kind of clearance your cat has. Also note logs in both of the main drops. One barely visible in the top one and one submerged in the bottom drop. So Dagger Falls may not care at all that you aren't planning to portage. Steep ( and likely snow covered) hill to climb up to start the portage and steeper hill to slide, stumble, roll down on the other side...if it's not snow covered...then it will only be slide unless you fix ropes.
Found the pic of all the stuck boats. Not great quality but still....