I don't have a ton of Instant Pot "only" accessories, I've been able to use things I already had for most things. I did break down and just bought this Oxo lifter/trivet. I used it this morning for PIP rice and no more burnt fingers! It's sturdy and not floppy like I feared. It lifted a stainless steel bowl with 4+ cups of cooked rice right out.
Another thing I had already that has served me well in the Instant Pot is the Lekue bag. I use this exclusively for hard boiled eggs. I was having problems with some of my hb eggs cracking during the cook. I think it was because they would touch the metal sides of the pot while cooking as I load up the metal trivet with 8-10 eggs at a time. Since I have been putting the eggs in the bag, not a single cracked one has been found. It also allows for the eggs to be lifted out wholesale and put in the ice water all at once. I've had the bag for years but never found a good use for it until now.