To help organize nested instance properties in the properties panel, it would be great to have them collapse inside their parent component in the list.
E.g I have made a component with several cards. The card component allows me to turn on and off the title, text, image, and button. I can also change any of the text from the properties panel. → When I use an instance of the component in my designs, I must scroll through all the open nested properties before I can edit card number 7. If I were to see an accordion with cards 1-7 with their nested instances hidden beneath, it would be less confusing and much quicker.