It's not really a bug so much as a "doesn't work the way you'd think" but it's not a missing feature...
I'm just starting to look at Render To Texture as a solution to my problem and it is looking pretty handy so far. But since I'm a noob maybe I'm doing it wrong. Anyway...
If I render to texture (hereafter "bake") with denoise, the denoising is not saved to the baked texture. If I bake many objects it looks like the denoising doesn't even happen.
This makes sense because I can mess with the denoise amount after the render. So it's a post-effect handled by the vfb, I guess. And the bake gets saved as soon as the render is over and before the vfb takes change. It makes sense.
So I can bake one object. Then save the denoised version by hand. But I've got four furnished apartments and a lot of manual work ahead of me. This one little efficiency would be nice.