I know this is long down the road; however, since most stations have a very distinct visual signal, is it possible to allow the operator to save the person's call sign to distinguish who they are when the are talking. That would be a very cool thing to see.
If you use the N1MM logger and connect to a spotting site, you will see callsigns on the bandmap screen. Then, as you tune across the band with your Flex you will see callsigns pop up on the top left of the logging screen.
This is a practical way to see station calls and its ready to use. There are other loggers that will show call signs too.
Regarding the distinct visual signal, on the HF bands, I cannot see distinctions between most of the signals. On VHF FM, many stations have a distinct "signature" that can be identified. These signatures have been used to identify interfering stations and pirates.