migration devices and .pof files

[Altera_Forum]

I have a simple question about migration devices in Quartus II. I have a design where the board could be populated with an EP4SGX230DF29C4 or the same part in either the -180, -110, or -70 size. The pinouts are the same and the design fits into the smallest part. 

 The FPGA is configured serially using a .pof file loaded into an EPCS configuration flash.   I have selected one of those parts as the target device and the other 3 as "migration devices". Is Quartus supposed to produce a single .pof file which can be used to program any of the 4 devices? Or do I have to select each device as the target device and re-compile the project to create 4 unique .pof files? In that case, what is the benefit of selecting migration devices?    Thank you in advance for any assistance.

[Altera_Forum]

you will have to recompile for each part. 

 the advantage of device migration is that Quartus will check your pinout to make sure it is legal with any of the devices you may migrate to. for example, higher density devices in the same package may have fewer user I/O and more VCC/GND pins. migration will make sure you don't use any of the pins which are legal in the small device that may not be usable if you migrate to one of the larger (logic wise) devices.

[Altera_Forum]

you may want to look into a shell and/or Tcl script to create programming files for each one of your migration devices. automation would take a while to run 3 fits on the same design, but would be less tedious for you. :)

[Altera_Forum]

Thank you for the concise answer.