My pro tip for making stocks or braises using pressure cookers is to use the pressure cooker as the first step of the process. Because pressure cookers are a sealed environment nothing you cook will reduce, and reducing any cooking liquid increases the flavor. For example, if you're making chicken stock for soup later, make the stock in the pressure cooker let it cool and put in the fridge or freezer for later. When ready to make soup, reduce the stock down by about 1/3. This is greatly enhance the flavor.
For braises, I will do a big pot full of beef short ribs braised in red wine and chicken stock. When they are done, I let them cool and put the pot in the fridge. The fat will form a barrier over the top of the pot like a confit, which will preserve the short ribs for a while. When I'm ready to make the short ribs, I remove most of the fat from the top of the pot and dump all the liquid in a saucepan and reduce the sauce down, when its almost done, add a chunk of butter and stir and add in the short ribs to come back up to temp. While the short ribs are good straight out of the pressure cooker, they are way better with this method.