I’m vegan and am currently doing 16:8. Feel perfectly fine but I’ve been vegan since 2011, so I’m used to it. I’ve just been making sure to get enough fiber (easy to do on a vegan diet tbh) and make sure I get in some fats so I stay satiated. I think it is definitely safe and healthy, I would say you just have to make sure you are getting the basic necessity of macros like protein and eat a lot lot of veggies to get the sufficient vitamins.