It's not really buried, though. It's behind a layer of acrylic, that in my case wasn't even on, and was quite literally facing the router. Supposedly (according to the docs) the ESP32 module can be replaced with one with a connector in place of the antenna so you can attach an external one via a pigtail. Replacing it does require a hot air reflow station though. It seems to be fine now that i've moved it about 5m closer.