elf files for bootloaders

[zemanj]

It's helpful to have the production bootloader *.hex files in the repo, however, what I am missing right now are the corresponding *.elf files.

Knowing the addresses of the symbols defined in a bootloader from its elf file would allow accessing SPM functionality directly from within a sketch (e.g., for writing flash memory pages etc.).

Would it be possible to include those files in the repo?

[MCUdude]

The Optiboot bootloader that Arduino boards are shipped with doesn't have any "write-to-flash-from-user-application" functionality, so providing elf files wouldn't help you here. However, 3rd party Arduino cores usually use newer bootloaders that have this kind of functionality, for instance, MiniCore.