Hi Hon, if you follow the guidelines keep them upright as possible and never put food in their mouths then they shouldn't ever choke, N has been doing it 3 weeks now and gagged a fair bit at first but he's soon got the hang of how much to put in his mouth and how far and now he just coughs to dislodge any big lumps!! Gagging is hard to watch at first but trust your baby and don't intervene and they will surprise you! I remember N gagging for about 5 mins and I left him as I could see he was breathing, making noises etc, eventually after much tongue rolling he spat out the biggest chunk of broccoli!
To me gagging is easy to spot they make noises you can see their tongue moving, they are breathing, whereas choking they go silent and can't breath. Choking is very very rare whereas gagging could happen 2 or 3 times in a meal especially at the start. Just tell the doubters that ALL babies need to learn how to chew & swallow solid food so all babies will gag at some point but blw babies gag more because their gag reflex is still so far forward which actually puts them at less risk as they will gag before a lump gets anywhere near the back of their throat, whereas as babies get older it moves further back so they aren't as equipped to get lumps out. Also my friend is doing tw and she had a gagging incident on a puree the other day so it's not always a blw thing.
It's just a perfectly designed safety mechanism which the body uses to prevent food that hasn't been chewed and is too big to swallow from getting anywhere near the back of the throat, not something to be frightened of!