Preheat your oven to 250°F (120°C). Line 1–2 large baking sheets with parchment paper or silicone baking mats to prevent sticking and make cleanup easier.
Place the mini pretzels into a very large mixing bowl so you have plenty of room to stir and coat them evenly. If doubling the recipe, use two large bowls or your largest mixing bowl.
In a medium bowl or large measuring cup, whisk together the melted butter, neutral oil, everything bagel seasoning, garlic powder, onion powder, kosher salt, sugar (if using), crushed red pepper flakes (if using), Worcestershire sauce, and Dijon mustard until well combined and fragrant.
Pour about half of the seasoning mixture over the pretzels and stir gently but thoroughly to coat. Add the remaining mixture and stir again, scraping the bottom and sides of the bowl, until all pretzels look glossy and speckled with seasoning.
Let the coated pretzels sit in the bowl for 5–10 minutes. This resting time allows the flavor to absorb slightly and helps the coating cling better during baking.
Spread the seasoned pretzels in a single, even layer on the prepared baking sheets. A little overlapping is fine, but avoid deep piles so they dry evenly.
Bake at 250°F (120°C) for 45–60 minutes, stirring every 15 minutes and spreading the pretzels back into an even layer after each stir. They are done when they look dry rather than greasy and smell toasty and fragrant.
Remove the baking sheets from the oven and let the pretzels cool completely on the pans. They will continue to crisp as they cool. Taste once cool and, if desired, sprinkle on a small amount of additional everything bagel seasoning while the pretzels are still slightly warm so it sticks.
Transfer cooled pretzels to a serving bowl, or store in airtight containers or zip-top bags. Serve for parties, snacks, or package in jars or treat bags for gifting.