Add beans, water, and salt to your instant pot. Cook on manual, using high pressure, for about 25 minutes (20 minutes for firmer beans, 30 minutes for very soft beans). Allow the pressure to naturally release.
Remove the lid, and pour the beans into a strainer. Rinse with cold water and set aside.
Set instant pot to saute and heat the bacon until it starts to brown. Drain some of the grease, then add the onions (optional) and cook until tender.
Turn the instant pot off and add ketchup, bbq, chilies, syrup, and mustard. Stir, making sure to scrape the bottom of the Instant Pot. Add the beans back in to the instant pot and stir until completely combined.
Replace the lid, turn the steam valve to sealing and cook on manual, using high pressure, for 15 minutes. Natural release for the pressure. Open the lid and stir, then serve warm.
Notes
If you want to add more spice, try substituting diced jalapeños for the green chilies. Try a spicier BBQ sauce (we love Stubbs Sweet Heat) or mustard. You could also add a pinch or two of chili powder.