You’ll gain some weight for sure, but it’s water not fat so don’t worry. I always break my dry fast with baking soda (Like you mentioned) and then i eat as always after breaking a fast: try to stick to low/zero carb and dont eat too much in one sitting. I always break my fast with soft cooked eggs (like 2 for example) few hours later I usually eat some tofu with low carb vegetables.
I’ve done a few 3 day dry fasts and literally just ate a couple pounds of steak. People worry too much about all this. From my experience if at that point of your fast you wanna end it but don’t have hunger drink salt water and electrolytes. 3 days is where the dry fast and any fast in my experience starts to get more serious it’s kinda the cut off. The only time I would be concerned about ending a dry fast with protocol is if it is around 4 days and beyond that then you just gotta be smart and give your body time to get water and electrolytes. This has been my experience and I was extremely ill.