Add priority option for the task like High, Medium ,low and very low
You could do that by using tags with exact these names. Then search by tag name and add the search as a favorite to your project list. That may not be exactly what you are looking for but it is very similar and - in my case - is very hand.
Yeah, we do a similar thing with drop-down custom fields. The slight advantage there is that you can change the drop-down option very easily in the task list, without having to delete one tag and add another.
+1 to custom fields! This is a super helpful use case. https://asana.com/guide/help/premium/custom-fields