Peel and core the apples, and cut into small chunks. Place in a saucepan. Add the raisins, orange juice, lemon juice, brown sugar, maple syrup, cinnamon, vanilla, and lemon zest. Stir to combine. Cook over medium heat, stirring occasionally, until the apples are fork-tender and the liquid is syrupy. Transfer the compote to a bowl and set aside.
Lightly butter the bottom and lower sides of the inner pot to help avoid sticking. Add the water, milk, oats, and salt, but do not stir. Close and lock the lid, making sure the steam release handle is in the sealing position. Cook on high pressure for 9 minutes. When it is finished, release the pressure naturally, which will take about 15 minutes. Turn the steam release handle to venting, releasing any remaining steam. Unlock the lid and open it carefully.
Scoop the oatmeal into bowls and top with a tablespoon or two of the apple compote. Serve immediately.