migrating grub from BIOS to UEFI loses /etc/default/grub

[Harald Dunkel]

Hi folks,

if I migrate a bookworm installation from grub-pc to grub-uefi,
then grub-pc.postrm removes /etc/default/grub on the final purge.

AFAICT /etc/default/grub is still processed for UEFI, so why
is it deleted?

Regards
Harri