Field Research rewards: Do encounters have higher IVs?

Level 15 trash

Quest encounters appear to have IVs each at 10-15, same as raids and eggs, and are level 15. At the lowest that is 66%, which is the second highest overall appraisal rating (66%-80%).

https://pokemongo.gamepress.gg/pokemongo-iv-calculator#/

Mine have all been "certainly", they seem to be better than wild catches but not better enough to matter.

My first encounter was a 100% gastly.