I’ve just changed my default kernel via grubby. Thanks again, @vgaetera. I tried to figure out the commands myself and then confirmed they matched your suggestions.
One (unimportant) question. I believe I could have achieved this with either of these commands. If there’s a reason to prefer --set-default, I’d be curious why.
--set-default=kernel-path
The first entry which boots the specified kernel is made the default boot entry.
--set-default-index=entry-index
Makes the given entry number the default boot entry.
Anyhow, I’ve set the default to my latest kernel:
james@mach:~$ sudo grubby --set-default=/boot/vmlinuz-6.11.7-300.fc41.x86_64
The default is /boot/loader/entries/5cf058c1ad62496fbb8d9914399e6db6-6.11.7-300.fc41.x86_64.conf with index 0 and kernel /boot/vmlinuz-6.11.7-300.fc41.x86_64
james@mach:~$ sudo grubby --default-kernel
/boot/vmlinuz-6.11.7-300.fc41.x86_64
Was considering rebooting, but I now understand why @gnwiii recommends removing rhgb quiet (see: What does rhgb boot option do?), and that seems like a smart change to make before rebooting. Will try that tomorrow night.