Does json_decode() still seg-fault with bad JSON? That's really really poor. It needs fixing.
"It's better to have fewer connections with larger datasets" - Modern smart phones have loads of memory compared to phones of old but there must be a point at which a really large dataset is actually problematic in itself.
Developers should just be aware of all the resource limitations that you get on embedded development. Restricted memory, processor, bandwith,; slower connection times; and so on.
Finally test on the most rubbish platform that will be using your service. Not the best!