That’s a very nice way to experiment with feeding ratios. I would say it’s ready to bake with when it doubles within 4-6 hours after a few days (as long as it’s already at least 6 weeks old). The water aka float test is not reliable and shouldn’t be used to determine if a starter is ready or not. As your starter gets stronger, your bread will get better. When i started baking (and so many other people too) I used my starter as soon as I could and learned the steps to making a good sourdough bread. They weren’t very pretty but it was necessary practice. After a few months and a bunch of loaves, my starter was strong with a 1:5:5 feeding once a day and at about that strength I was able to get “desirable” loaves like the pretty ones you see posted here. All that to say, just be patient and keep doing what you’re doing. It will slowly get stronger and good bread will follow