Have you noticed if re-gaining is easier than new gaining? Anecdotally, that's been my experience, and statistically, most people who intentionally lose weight go on to regain it (and then most of them gain more). Personally, my body seems to like being about ~5-10 lbs lower than my highest weight during intentional gaining.
I haven't noticed a difference. I'm regaining the weight at about the same rate that I initially gained it.
Oh yes, people who intentional lose weight do tend to blow back up easily, but that's a different situation. In their case, they were already overeating, and then went on a diet and/or started exercising. When their old habits kick back in, the weight piles back on easily.
My situation is almost the opposite. I normally eat a healthy, low-carb diet. I gain weight only through heavy whipping cream, adding it onto my normal diet. When I took a break from gaining, I just kept eating my regular diet, and my body naturally lost a lot of weight. I did not retain anywhere near as much weight as I had hoped.
This next part surprised me. I have actually hit plateaus as I was regaining! I couldn't believe it. There I was, much lighter than my previous high of 295 pounds, and struggling to break through a plateau.
Once I reach my goal weight, my next challenge will be figuring out how to maintain it.