The settings have always been interchangeable with driver configurations.
This is the sole reason mon0 was created in aircrack. For instance using madwifi (as example) injection drivers could be loaded for mon0 and then subsequently mon1 linked to the same interface(wlan0/X) could stay put in raw packet capture mode.

Use cases are really dependent on what you are trying to do and driver capability.
The entire point of device interface alias's is so that each subsequent alias can retain its own configuration variables.

In other words some advanced configurations rely on that of device alias's.

One use case i can think of off the top of my head would be if i wanted to use mon0 for cleven/Fas with injection and then mon1 for wireshark weakIV silver/gold/platinum packet counting.

Another use case would be different assigned mac address's for each alias. Note: I've seen this used in some advanced chopchop attacks and worked well on some routers, on others not so well.

I'm sure there are other use cases that are as equally important however that haven't come to mind.

All im really saying is, if you want to eventually integrate more advanced attacks in the future and you want to grow., its best to stick with tradition, keeping mon0 around where you can.