I've released a Flagfox 5.2.4 update, primarily for Firefox 52 ESR, but it'll work in anything else Flagfox 5.2.x runs in. You can get it here:
https://flagfox.wordpress.com/2018/02/28/february-updates/

(Just FYI: Even after I eventually discontinue providing these updates, I have no plans to change the IPDB file format any time soon, at least not likely in a backwards-incompatible way.)

I've released a Flagfox 5.2.4 update, primarily for Firefox 52 ESR, but it'll work in anything else Flagfox 5.2.x runs in. You can get it here:
https://flagfox.wordpress.com/2018/02/28/february-updates/

It's not the rendering speed, per se. There's no API to get IP addresses after requests, and fetches of cached requests leave their IP field blank. A manual refresh forces a new actual request and thus fetch of the IP, at which point it works. If you're getting the globe when a refresh will cause it to change to a flag, then either Flagfox was loaded before the page was or it somehow got confused and forgot a cached IP, somehow.

Due to the API limitations here, I've got to listen to IPs ahead of time and cache them for when needed. Caching is easy; caching without keeping everything cached forever and becoming a giant memory leak, is more difficult. Flagfox 6.0.1 has some cache improvements, with more likely to come in future updates. TL;DR: Working on it.