A useful feature for locating a device that’s broadcasting would be some way to indicate “warmer” or “colder” as you move about with the Flipper in hand. Lock in a frequency or protocol, and the LED can blink faster as the signal is stronger, or go from red to green. Or slow beeps of the speaker get faster as the signal gets stronger.
I’m not well-versed in the physics of RF signals, but might it also be possible to build a GPIO add-on with additional antennas that are more directional for the same purpose?