how to dynamically create composite sprite textures?

Question

I'd like to build complex sprites at runtime by creating a single composite sprite (made of many child sprites) and capturing the textures to reuse them as customized sprite sheets.

I'm new to the engine, so perhaps this would cause it issues?

Does Godot have any issues (memory or performance) with managing a variety of dynamically generated textures?

Would this require an offscreen viewport to perform render and capture?

Any suggestions would be appreciated! Thanks!