Rotation-invariance is probably not really a thing you want. The visual world is not, in fact, rotation-invariant, and the "up" direction on Earth-bound, naturally-occurring images has different statistics than the "down" direction, and you'd like to exploit these. Animal visual systems are not rotation-invariant either; an entertainingly powerful demo of this is "the Thatcher Effect" (https://en.wikipedia.org/wiki/Thatcher_effect).
Reflection across a vertical axis, on the other hand, often is exploitable, at least in image recognition contexts (as opposed to, say, handwriting recognition). If you look at the features image recognition convnets are learning they are often symmetric around some axis or other, or sometimes come in "pairs" of left-hand/right-hand twins. As far as I know nobody has tried to exploit this architecturally in any way other than just data augmentation, but it's a big world out there and people have been trying this stuff for a long time.