Make flag default behavior for git command (commit and rebase)

I want to specify the flag --keep-empty and --allow-empty to be the default behavior for rebase and commit, respectively. Is there a way to do this?

As far as I can tell, there isn't a way to do this with git config.

I only want to do this for a specific repo, so I want to avoid aliasing the command in bash.

I especially want to do this for rebase, as there's the high probability of erasing important, but empty, commits by accident.