If you need to scale that up for some reason or are working with 10-bit displays then just use RGBA16F textures. No reason to stick to 32-bit here. GPUs are perfectly happy to work with half-float textures.
Although if you want to keep 32-bit textures you also shouldn't be doing linear premultiplication like the article suggests, you should be using sRGB instead.
Although if you want to keep 32-bit textures you also shouldn't be doing linear premultiplication like the article suggests, you should be using sRGB instead.