Bring a large sauce pot of water to a boil. Add the rice noodles and cook until just tender, 8 to 10 minutes. Drain and rinse with cold water, then return to the pot and set aside.
While the water heats and the noodles cook, prepare the pad thai.

• Finely chop, press, or grate enough garlic to measure 1 teaspoon [2 tsp].
• Trim the root ends from the scallions; thinly slice the scallions on the diagonal, keeping the white and green parts separate.
• Rinse the shrimp, then drain on a paper-towel-lined plate and pat dry.
• Crack the eggs into a medium bowl. With a fork or whisk, lightly beat until just blended.

In a large frying pan over medium-high heat, warm 1 to 2 tablespoons oil until hot but not smoking. Stir in the garlic and white parts of the scallions, season with salt, and cook until starting to soften, 1 to 2 minutes. Stir in as much kimchi chile flakes as you like. Add the shrimp and cook, turning once, until firm and cooked through, 1 to 2 minutes per side for regular shrimp, 2 to 3 minutes per side for jumbo shrimp.
Add the rice noodles, eggs, and half the pad thai sauce base and cook, stirring often, until the eggs are set and the noodles are well coated with the sauce, 2 to 3 minutes.
While the pad thai cooks, prepare the remaining ingredients.

• Using the bottom of a bowl or cup, lightly crush the cashews for garnish.
• Thinly slice the snap peas lengthwise for garnish.
• Cut the lime into wedges for garnish.
• Coarsely chop the cilantro.

Remove the pad thai from the heat, stir in the cilantro and green parts of the scallions, and season to taste with salt and pepper and as much of the remaining pad thai sauce base as you like.

Transfer the pad thai to individual bowls. Garnish with the cashews and snap peas and serve with the lime wedges.