Roasting should make a tomato taste more like itself, not like generic sweetness.
Separate concentration from brightness
We roast part of the tomato hard for depth and keep a smaller portion fresher for acidity. Blending the two gives more range than trying to make one batch do every job.
Use the tray juices
The liquid around roasted tomatoes contains dissolved sugars, salt and aroma. Reduce it separately if it is watery, then add it back in increments. That keeps the soup concentrated without overcooking the flesh.
Finish with a cold note
Basil cream, raw olive oil or a small amount of sharp vinegar gives the palate somewhere to go after sweetness and char. The last ingredient should open the dish back up.
