Can one force a config file that has a private string from another area (Same ISP of course)? I don't think so but just asking just in case.
What is stopping you from trying?
neo_ can do it, as a matter of fact, he can just edit the right string right in there and keep pushin....hahaha
If its not forceware/haxorware, you can just patch the stock firmware ti_tftp (if its a puma5 modem) to replace the config served by your isp with one in your nvram.
SBG6580 is a Broadcom chipset