Grailing Chloe

Her HP is quite low for a 4* Archer, so I would grail and max HP fou her.

She is worth lv 90.
Typically when you set Art Team for her.
For gameplay, Lv90 Shirou is great when you have critical team for him.

In my opinion you should since she has a lot of positives. She has NP 5 if you fully completed the event, good skills and really good damage and is regarded as one of the best wellfare servants by many people.