I haven’t used openSUSE in a year or two, but I did really like it. You can easily adjust the Grub timeout with YaST. It was under System > Bootloader.
I ultimately stopped using openSUSE because I kept getting conflicts with zypper and Packman, but that was probably my fault. If you’re on Discord, the openSUSE server is one of the more friendly ones I’ve seen and very helpful.