Set the oven to 425°F and arrange the bacon slices in a single layer on a parchment-lined baking sheet. Keep the slices from overlapping so the covered portions don’t stay soft.
Bake for about 10 minutes, checking for fully cooked, crisp bacon, then remove the sheet and let the strips cool completely. The cooled bacon should feel firm and snap easily rather than bend limply.
Whisk the light mayonnaise, Greek yogurt, garlic powder, onion powder, kosher salt, and measured jalapeno liquid together in a large mixing bowl while the bacon cooks. The dressing should look smooth and evenly seasoned, though the brine may make it slightly loose.
Finely dice the red onion, slice the scallions, and chop the drained jalapeno rings. Small, evenly sized pieces distribute the onion flavor and pepper heat more consistently.
Pull the cooled cooked chicken breasts into shreds or cut them into bite-size pieces. Avoid oversized chunks so the dressing can coat the chicken evenly.
Fold the chicken, red onion, scallions, and jalapenos through the dressing, then incorporate the shredded cheddar. The mixture should look evenly coated, with cheese and chopped vegetables scattered throughout.
Crumble or chop the cooled bacon into the bowl, mix until evenly distributed, and taste for seasoning. The finished salad should be creamy and scoopable, with crisp bacon pieces and a tangy finish.