[nmstoker]

I wonder whether USB Network might be an option to reduce the latency a little. L

Plus then keeps the Pi WiFi free for regular use rather than as a private AP network.

[RBerenguel]

The Kindle can’t handle USB networking, so it wouldn’t be a viable option. The private network is only needed if you are not in a WiFi capable area: at home I use it without AP

[obrajesse]

Historically, at least, USB networking was pretty straightforward to enable on a jailbroken Kindle.