I currently have just one openSPOT 4 Pro. I am considering buying one or more additional openSPOTs. My plan is to set them up on either different modes for cross mode operation or different talkgroups on the same mode. Assuming each frequency is separated by 25 (or more) kHz, are there any other concerns that I should be aware of? I would use a portable radio to scan the two (or more) frequencies.