I haven't taken that route either, but I have hiked through Pastavagge and Skájdásjvágge looks narrow and steep from that direction.
However more useful information is provided by Claes Grundsten who writes about Skájdásjvágge in his guidebook "Vandra kungsleden 2". Freely translated:
Skaitatjvagge
The name of the valley means "between the creeks", and in the upper part the valley is wedged into two water-bearing branches with a mountain-ridge between them. This is one of the routes in Sarek with the highest altitudes, the pass is situated 1610 meters above sea level. It connects Pastavagge with Rapadalen and is valuable as a shortcut. However, it is an unusual burst of effort to get to the crest. The passage is rather a climb than a hike. When starting in Pastavagge you walk along the west side of the watercourse and wade it higher up in order to follow the ridge between the ravines. The slope to the pass, where you meet an impressive and wide view, is broad and boulder-dominated. The south-side is steeper and demands awareness. You keep to the west side. Down by Vassjalåptå you either choose between taking the route to Vassjavagge and further over Jåkåtjkaskalako to Aktse, or down the ravine where Alep Vassjajåkåtj through which you reach Rapadalen. The route over the pass stretches 10 kilometers from valley to valley.