Stir wafer crumbs, pecans, powdered sugar, lime zest, and kosher salt in a large bowl.
Whisk tequila, orange liqueur, lime juice, and agave in a small bowl until smooth.
Pour the liquid into the dry mixture and mix until evenly moistened. Let it rest 5 minutes to hydrate.
Combine granulated sugar, extra lime zest, and flaky sea salt in a shallow dish for coating.
Scoop and roll 1-inch balls with damp hands. If crumbly, add 1–2 tsp more lime juice or agave.
Roll each ball in the citrus sugar to coat. Chill 20–30 minutes until set, then serve.