Pour the water into the insert set in a 5-, 6-, or 8-quart InstantPot. Put the wingettes and/or drumettes in the insert and lock on the lid.
For all Instant Pots, set to Pressure Cook or manual, low, for 12 minutes. Make sure the valve is closed and press Start.
When the pot has finished cooking, use the quick-release method to bring the pressure back to normal. Unlatch the lid and open the cooker. Use kitchen tongs to transfer the chicken pieces to a nearby large bowl. Use hot pads or silicone baking mitts to pour the water out of the (hot!) insert and wipe the insert out before returning it to the machine.
For all Instant Pots, choose Sauté and set to medium, normal or custom 300°F. Select 5 minutes and press Start.
As the pot heats, mix the Frank’s RedHot sauce, butter, Worcestershire sauce, sugar, garlic powder, and pepper in the insert. Continue cooking, stirring frequently, until bubbling, about 3 minutes. Meanwhile, whisk the cornstarch and water in a small bowl until smooth.
Whisk the cornstarch slurry into the bubbling sauce, then continue cooking, whisking constantly, until thickened, less than 1 minute. Turn off the SAUTÉ function and use hot pads or silicone baking mitts to transfer the (hot!) insert to a nearby wire rack to stop the cooking. Add the wings, toss well, and cool for a minute or two before serving hot with little bowls of blue cheese dressing for dipping.