automagic entry grub options

[ms419@freezone.co.uk]

How can I change the grub options in the automagic entries?

I've been over the documentation, and I understand I can change the 
"root" and "kernel" grub options using the "kopt" and "groot" automagic 
options; however, I need to change the other grub options in the 
automagic entries.

For instance, I'm running a headless machine in a remote, inaccessible 
location. I'm always nervous installing a new kernel. I would like 
automagic entries for new kernels to include "savedefault fallback", 
incase the machine doesn't boot.

How can I do this?

Thanks!

Jack