I think I have, but maybe I haven’t been paying attention. When I update Tumbleweed and it installs a new kernel it updates grub to reflect the new kernel. When I reboot the new kernel is installed. To my surprise it seems that new kernels for Linux Mint are also being installed. I’m pretty sure that didn’t use to happen. I assumed I needed to take the Linux Mint entries in it’s grub.cfg and merge them in with Tumbleweed’s grub.cfg. However it appears that Tumbleweed is updating Linux Mint’s grub entry also.