BootSelector is a tiny GUI utility for setting any grub menu entry as default.
It also allows you to reboot into any OS/kernel in your grub menu.
The initial version has been tested on the latest Ubuntu 24.10 and should work on other Debian-based distributions as well.
An RPM for fedora will be released soon after more testing is done.
With the Reboot Into Selected, will this modify the next boot only without changing the default?
Yes, it only reboots into the selected entry ONCE without changing the default one.