that's the direction i was thinking as well, just trying to turn the train of thought into something coherent.
i suspect the base programming on those uv5g will be similar what shipped on my Btech gmrs50x1, channels 1-22 were the 7 low power simplex frequencies (1-7), the 0.5 watt FRS frequencies (8-14receive only on mine), and then the 8 high power simplex channels (15-22). Slots 23-30 were set up for repeater use, with the +5.0mhz transmit offset baked in, though they used the same receive frequencies as 15-22.
if i have a local repeater that the output is 462.575, i'll be able to hear it whether i'm on channel 16 or channel 24, because both receive on 462.575. However, on transmit, channel 16 is transmitting on 462.575 as well, while 24 will incorporate the offset and have me transmitting on 467.575 (which is where the repeater is listening).