MRT RenderTextures: log says "colorHandles[0].object->backBuffer == depthHandle.object->backBuffer"

I've been using multiple-render-targets for over a month successfully now.

The setup has 4 RenderTextures: [0]=ARGB32, [1]=RGHalf, [2]=RGB565, [3]=Depth

This worked fine all the time with Camera.SetTargetBuffers, all RenderTextures were created only once during app start-up and destroyed on exit.

So today I thought "I'm gonna be a smart one" and disable RT [2] if a certain user-config-setting indicates it's never needed or sampled. Means, instead of "create once during app start, destroy on exit", I now have to recreate the tex array as that config setting is toggled. (OK I could do acrobatics of keeping the others alive and resizing and reshuffling the array, but hey brute-force doesn't hurt during code-prototyping.)

That actually all works perfectly fine but whenever said user-config-setting is toggled (and only then) and the rendertexes-array is recreated, I get the following the 3 new, never-seen-before messages:



Odd, huh? What does that tell me? Looks like a warning I should heed, even though everything works smooth as silk!

 

After a restart of Unity, now when recreating all RenderTextures, I find a console warning (not error) message:

RenderTexture: Resolving non-color surfaces.

Once so far Unity also crashed when I triggered recreating of all MRT rendertextures+renderbuffers. Seems to happen only very rarely but sometimes.

What the heck is the "safe" way of recreating multiple-render-target-buffers at runtime?