Miso-Glazed Salmon With Sushi Rice

Bring rice, a pinch of salt and 2½ cups cold water to a boil in a medium saucepan over medium-high heat. Stir once, cover, and reduce heat to low. Cook until water evaporates and rice is tender, 18–20 minutes. Remove from heat and let sit, covered, 10 minutes.
Whisk sugar, ¼ cup vinegar, and 2 tsp. Diamond Crystal or 1¼ tsp. Morton kosher salt in a small bowl until sugar dissolves. Stir into rice; re-cover. Let sit until ready to use.
Whisk maple syrup, miso, tamari, ½ tsp. red pepper flakes, and remaining ¼ cup vinegar in a small bowl. Set glaze aside.
Heat oil in a large nonstick skillet over medium. Season salmon with salt; cook, skin side down, shaking pan occasionally, until skin is very crisp and deep golden brown, 7–9 minutes. Turn over and cook just until flesh is very lightly browned ( it should be nearly cooked through), about 2 minutes. Using a spatula to hold back fish, pour off fat from skillet.
Reduce heat to low and add reserved glaze to skillet; cook, stirring occasionally, until it begins to thicken, about 1 minute. Baste salmon with glaze and cook, basting occasionally, until glaze evenly coats fish, about 1 minute.
Divide rice among plates and top with salmon. Drizzle with any leftover glaze over; sprinkle with scallions, sesame seeds, and red pepper flakes. Serve with lime wedges if desired.