At a cost of $300, I hired a structural engineer to comment on this case where two rafters are cut. He came up with two designs, one leaving the stair unit in place, another eliminating it.
The elimination plan, my original question, was as thought, plus a little bulkier. He wanted one 2x4 sistered on each side of the missing section, extending two feet on each side. In this case, that is six foot 2x4s. For fasteners, he wanted 12d nails 3" on center, twice what I thought.
Thanks to you here for suggesting the stairs be retained. However, his design is different from building a window opening header/jack type of frame. In a wall, the basic force is gravity compressing eberything straight down. Trusses are different, and have both compression and tension forces. I’ll explain in detail.
In summary, he wants a 2x8 tucked under the peak, running along the ridge, and two 2x8s running the same direction, attached to the nearest braces of the W truss just above the base cord. He wants Simpson connectors, not calling out specific models. I interpret to essentially be hurricane ties, h2.5 at the peak, h4 at the base.
The new member at the peak essentially keeps the peak from falling. Rafters are under compression, to my understanding.
The new members near the base look to help the walls from spreading, as the base cord is under tension. There is also some downward force on them, given the nature of thw W aspect.
At any rate, I appreciate the comments here and do not regret having this fellow look at the job.