When using VK_EXT_opacity_micromap, it seems that VkAccelerationStructureTrianglesOpacityMicromapEXT::indexBuffer device address should be aligned according to the indexType alignment (e.g. to 4 bytes if indexType is UINT32).

I don't see an obvious VUID for this, but I do see a GPU crash when the addresses are misaligned (on NVIDIA 590 drivers; I'd guess the issue is that the driver uses aligned reads and ends up getting incorrect index values if the data is misaligned). The crash goes away if the index data is aligned properly. I'd expect the validation layers to flag this.