The expanded memory option would be very useful but I still believe that you should also think about to capture 10 us packets with 250 MSPS, perform a overlapping FFT and transfer the spectrum in real time over the USB3. So finally there is the possibility to analyze long records with a very fine time resolution. The fine time resolution is needed because there are short packets (minimal 44 us duration for Bluetooth 5 packet) in the 2.4 GHz Band. For the persistence display you do similar things in the FPGA, but instant to accumulate – transfer the spectrum every 10 us.