I've heard the strand float isn't always reliable. My hair was still floating hours later, so I pushed them down into the water, and they popped right up except for one tiny piece of a strand that floated just below the surface but still didn't sink. So then I did the other test, where you quickly run your fingers down the length of a strand, from the roots down, and if it feels smooth, it's normal, very smooth/squeaky, it's low, and if it has some drag, it's high. I'm not sure how accurate that is either. For all I know, I'm wrong and I'm normal porosity. But, many products create white froth on my hair rather than absorbing, oil doesn't absorb on dry hair, my hair takes a very long time to dry (5-12 hours), strand was very slippery, and hair never sank, so the tests combined with how my hair behaves make me think I'm low, or low-normal since I color-treat.
Might have it formally analyzed in the future, but I don't see how knowing if I'm really low, or normal would make much of difference in how I take care of my hair. (I'm sure many people would disagree and say it is very important.) But what works for some people with the exact same analyzed hair types doesn't work for another. There's climate and weather, unique ingredient sensitivities, and personal taste to name a few (oily looking to one person is shiny to another, frizzy to one is a great hair day to another, one loves protein and gel, one hates them, etc.).
At the same time, I might have more luck trying products people like who have the same or similar hair properties than I would choosing from someone's who are completely different. But sometimes that's not the case either. There's just no guarantee the same products or routines will work for people no matter how similar their hair properties, and no one-size-fits-each type for how much protein vs moisture you need. There are suggestions, but there's trial and error involved. I would prefer exact instructions and a guarantee.
ETA: The main thing I do think would be very important to know is if your hair is damaged/high porosity as it will need a lot more tlc. But I think that's pretty easy for people to figure out on their own because it's probably going to breaking off with split ends all over the place.