Is it possible to mix 2D and 3D graphics in a single OpenGL ES 2.0 game, please?

I have plenty of 2D graphics in my game. The 2D graphics is represented by two triangular polygons (making up a rectangle) with texture on them. I use orthographic matrix to render the whole scene.

However, I need to add some 3D effects into my game. Threfore, I wish to use perspective camera to render the meshes.

Is it possible to mix orthographic and perspective camera in one scene? If yes, is there going to be a large performance cost for this? Is there any recommended approach to do this effectively? I wil have 90% of 2D graphics and only 10% of 3D.

Target platform is OpenGL ES 2.0 (iOS, Android). I use C++ to develop.

Thank you.