Is there a way to highlight all interact-able objects/loot in the game? While I’m trudging along I fear I’m missing a camouflaged jug or stump that has some unique loot inside it but I’ll never know because I’m B L I N D 
Mebbe a Bling Option could be added for us squinters.
There is no key that will highlight interactable items. If your cursor goes over such an item, it will highlight. So cursor waving on the screen is what most people do. Though, it’s still possible to miss the highlight if you aren’t paying attention.
I feel it’s an intentional design decision to make things only highlight when you “find” them with your cursor.