Vertical keepout for radio module.

[alberto.spagnolo]

Hello everyone,
my company is developing an ESP32-C3-MINI-1 based system with two stacked PCBs.
The top PCB mounts a GPS module and is entirely covered with a GND plane.
The bottom PCB mounts the ESP32-C3-MINI-1.

I couldn't find indications about the keepout distance (if any) above the module.
This device is going to be qualified to the Bluetooth SIG and we'd like to be sure that all the radio specificationss for the module are met.

Are there any prescriptions for this use case?
Thank you very much.