32x memory isn't that big of a jump if you go from storing a bunch of low res, low color count textures to a bunch of high res, high color count ones. I don't know if that's what's going on here but given the advertised "DirectX 8 → DXVK → Vulkan → MoltenVK → Metal" rendering pipeline I could easily see some leaky abstractions there that end up consuming a bit more memory than originally.