The package has at least one dependency that's now flagged as having a security vulnerability. I haven't checked in with the author but using unsupported packages will often bite you eventually (even though it may take years...)

It's probably worth noting that (near the end of 2021...) the package you recommend has not been updated in 4 years.

Not much US data but I was super happy to find geojson.xyz, since they have a simple index of a wide variety of data sources, all hosted on Cloudfront with CORS headers so I can test out my application on a bunch of primitive types.

I think my question should have a specific, concrete answer. For example, maybe "generally, RESTful encoding works better with caching servers" or even "it's unlikely to make any difference and is purely a matter of personal choice". I haven't been able to find any analysis of the situation or background on why there are multiple supported request encodings, so I was hesitant to just pick one and go with it.