I have the same problem that Faille has with V -- Otter was born (a week early) on about the 90th centile (give or take) and has grown so fast that he now is well above the 100th!

His head size is literally off the charts and only 6 inches smaller than his dad -- whose head is so big there is only ONE company that made helmet big enough for him.
I, too, worry that he is gaining too fast and is going to have obesity problems. But TBH, I have to trust he is doing what he needs. He is definitely a chunky baby, but happy and meeting his milestones just fine -- or even ahead. I admit that he isn't as mobile as he could be -- he CAN roll over, but just doesn't bother very often.

I put it down to it being hard to move that chub around.
So, PS, I wouldn't worry about Kian. Every baby does their own thing. I always say as long as they are happy, healthy, and hitting milestones, then don't worry. Everything is fine until proven otherwise.
As for weaning early -- I would make that decision based on other things than weight gain. I weaned early because Otter wouldn't have it any other way and was beyond ready. Besides, even when eating purees, they don't get a load of stuff from it at first, so I doubt it will help Kian gain weight. Milk is more likely to put weight on him. Weaning early may actually slow the weight gain even further.
S, great news about the Broc & Cauliflower with Cheese! We had that the other night and Otter devoured it. I wouldn't worry about feeding her the once either. One time isn't going to make or break BLW!