Yes. It violates the End User License Agreement (EULA) and copyright law. Your SketchUp projects could also be flagged if you share commercial work made with pirated plugins.

Is Twilight Render Free? Limits vs Pro for SketchUp - Coohom

If you love the trial and decide to buy, here is the official pricing (as of 2025):

Twilight Render LLC offers a of Twilight Render V2 Pro. After 30 days, it reverts to the "Hobby" version (free, but limited to 800x600 resolution and adds a watermark). There is no official permanent free Pro license .

A fast, free-to-download AI extension for photorealistic interiors/exteriors [28].