Vans aircraft have been doing their tanks in .032 for years with no more problems than any other aircraft, no cracks , no more flexing than the rest of the structure. The bottom line is aside from using bladders no fuel tank is going to handle impacting trees at upwards of 150 kmh( in motor vehicle terms) not even when fitted into cars and built out of steel . The best product for tanks is plastic, part from puncture damage I've seen heaps of them squashed and smashed into all kinds of shapes through accidents without bursting, problem for us is finding a shape that suits usually the limited spaces we have for fuel.
I built the extra wing tanks for my plane out of 1.2 alloy ( nothing exotic, just the standard crap all the suppliers carry for general fabrication ) they hold 15l each , have a single baffle longitudinally, and as I set them up to cross feed from the mains they only have a breather and a drain, works well . The reason I'd redo my tanks is to bring it back to one large tank per wing , and for aesthetics the welded tanks have the normal buckling that welding thin alloy produces, my plane being rag n tube you can see it all under the wing fabric. Doing the tanks with rivets and sealing the joins will produce a much tidier finish , good enough for my RV6 ,good enough for my SkyWolf