I thawed a butt ham by just bringing it up to pressure!
I have used a stove top PC for years.
I cook my potatoes in a PC for mashed potatoes, then add butter, can milk S&P.
Friends and family rave about them. I think it is becouse the potatoes are not water logged. I cut them up and just bring them up to pressure no need to cook longer.
Meatballs [frozen]and sauce plus extra water for 10 mins, and the flavor is thought out the meatballs. then cook it down.
Cook your roast with a large potato, when done remove and puree the potato with added water and add back to roast with veggies and pressure for 5 mins.
The puree potato will make your gravy for you.