You’re using the logging feature correctly. With “no wait” selected, the meter will be sampling continuously and writing to the SD card, so the effective sample rate will depend on your buffer depth and sample rate settings. These are visible in the app at the bottom of the screen.
So, for example, if you have it set to 125Hz, 64samples, you’ll get about 64/125=0.512 seconds between log entries (in reality slightly longer because of calculation time and time spent writing to SD).
If you want to get even faster, you can manually raise the sample rate in the app before disconnecting.
Hope this helps