List of latest bootloader/modem

So trying to find out where the latest modem and bootloader are for the G920T? Is there a comprehensive list of what is latest and greatest?

Thanks,

What's the point of updating the bootloader/modem, in simple language?

From what I understand there is some murky comptability issues with newer roms and older modems/bootloaders. The modem makes a little sense to me, network infastructure changes, the bootloader, not so much