I've been keeping an eye on Zoe. I'm interested in the concept of personalised testing, it seems to be the right direction, but not quite there yet.
I do understand that they need raw data, and that some form of standardised testing is helpful. However I rarely eat bread or cake or any processed carbs, and i don't fancy backtracking and eating muffins for a whole day, just so Zoe can measure my response, and tell me what I've already worked out for myself, and don't do anyway!
Same with what sound like the comparative swaps(?). If you can choose your own, great. Can you? It might be helpful for data to confirm that my body has a better response to a vegetable frittata for brunch when it's not followed by equal calories chocolate. (Totally random example, never happens.) However the swaps mentioned here I already know the answer to, both directly from my body, and from science.
I agree with pp about the need for more public facing information about what's involved, before signing up, it's currently very opaque.
So I'm following, with interest, from a distance. Until it can start where I already am, and build on that.