One minor issue with the version 20210410: The file
/etc/default/grub contains the line
GRUB_DEFAULT=saved, but not the line
GRUB_SAVEDEFAULT=true. So the last menu entry used when booting is not remembered, and the next boot still uses its old default menu entry.
This is easily fixed by entering the missing line into
/etc/default/grub and then rebuilding the grub configuration file via the command
sudo grub2-mkconfig -o /boot/grub2/grub.cfg.