This whole "cross-chain" is greatly overblown.

Nobody thinks anything is wrong with riding in low (small/small) yet riding crossed large to 2nd low is only marginally worse, and large to 3rd low is actually better. The same holds true in the opposite direction, and you can draw your own conclusions about the middle of a triple.

So, rather than obsess about it, understand that a properly set up bicycle allows riding in any combination, except possibly small/small on some 10s road bikes due to chain rub on inner face of outer ring.

So, feel free to shift according to the situation, ie. stay on outer ring, if you need only shift to the inner rears for a short while as you top a short climb. Of course, it's better for the chain, and more efficient to ride in aligned combinations, so try not to make a steady diet of more crossed combinations.

So, shift according to the situation, and don't fret when/if you find a crossed combination is working for you.