I took Terraria for a quick spin on my Switch 2 back when I 1st got it. Overall it runs smooth. I don't remember how it performed on the original Switch, but I have confirmed a majority of my Switch games run far more smoothly on Switch 2 compared to how they ran on Switch 1. It proves to be the same case for Terraria. I'll need to play around with it more to get a better feel when it comes to things like boss battles and invasion/pumpkin moon events.
It is worth noting that it would need to be updated specifically to be a Switch 2 Edition in order for mouse mode to work on it (which it could benefit from). There are no plans for a Switch 2 update/edition at this time. If that changes in the future, it will most likely be shared in a future State of the Game announcement from the developers. All I can confirm is that Terraria indeed still runs properly on Switch 2 and can be played the same way as Switch 1.
I will test if its possible to map the GL/GR buttons on the pro controller to some of the gamepad functions at a later time.