It's been done by good paddlers, fully loaded self support. They ran everything when the gauge was roughly 6.5, and Dagger went fine. However, they were solid paddlers.
If you haven't paddled the boat yet, I would take it out for a run or two before day one of MFS. All 10' self-support kayaks will feel more like a tank than your sporty river running Burn.
A lightly loaded Burn, or empty Burn, would be fun for soul surfing the big waves, and still give you nice stability in the larger rapids.
If you are comfortable in a smaller boat, and, if you have raft support, and since it's July, I would seriously try to give all of your gear to the rafters and surf every wave.