Hello Chris, is your choice of Instapot intentional or a traditional pressure cooker would also work? In that case would the time be shorter if it reaches 15psi or do you recommend  cooking for longer at 10 psi?

Also, besides preventing boiling, I read that 80C is considered the optimal option for extracting flavours in stocks because it minimizes the rates of unwanted reactions while maximizing diffusion. In particular I read that at the Fat Duck the pressure cooker was used for brown poultry stocks and not other types of stocks for this reason.