There’s a YouTube channel where the guy went from about 400 and he’s slim now, he does a more holistic style and interviews a ton of people who did it, I’d advise you check him out his channel is A Healthy Alternative
You are on your health journey, no matter what type of fasting that you do.Those electrolytes are always part of my routine whether i am fasting or not.I commend you on your efforts and belive that you will learn more and more as you go.
Also i like the bold move to aim for 40 days.
Drinking the juice will likely make you feel less tired and make it easier to break the fast when you do. I think if longer fasts work for you, do them. If you find you gain back a lot after or are getting burnout then switch to rolling 72s and focus on smaller healthy meals and maintaining weight loss in between fasting.