I wouldn't doubt if it's Chase, Smith or Waddle.
If we're looking at right now, 2021 season, I think Waddle might be the best immediate add. Parker, Fuller, Gesicki and Waddle cover the entire field, with Waddle getting a lot of use in the slot.
Long-term, who knows how much longer the team sticks with Parker, how injuries could affect his career. Who knows if Fuller is around longer than his current one year contract. When you factor that in, then Chase and Smith have to be considered as well.
The Tua factor would seem to favor Smith, maybe a little higher than Waddle.
In other words, I have no idea!