Right now choosing an Object/Json for a blueprint property is less than ideal because it literally displays as json to the user. However, this is not a great experience for the end user because Json is not nice to look at and some users might not understand it. Current implementation is shown in the picture with the red arrow below.

My suggestion is to create a better method of displaying object/json inputs to the user as maybe a popup if they click into the object. Such as the below image about user details. Maybe some nicer method of displaying key/value pairs when you click into the object on the entity screen.