8 weeks!!! yikes thats early. I'm suprised you didn't have problems. 8 weeks is WAY to early. Every baby is different, but thats pushing your luck to much. I don't even know an 8 week old who can sit up to eat, never mind swallow on his own. The chances of allergies, constipation, chocking, and other complications is just way to high.
Reflux babies usually get worse with solids. Especially if they are started earlier. An imature tummy is worse with reflux. Are you sure its reflux your dealing with and not something else? I can't see any doctor saying solids are OK at 8 weeks due to the risks involved. WHO recomends 6 months for a good reason.
Please don't take this as an insult, its not. I'm just shocked.
My Dad tried to get me to give DD solids that early saying it would make her sleep, and not spit up. I'm glade I waited because when I did start my DD who also slept 12 hours started waking 2-5 times a night, was constipated and threw up more. My DD was a lot older then yours too.