Slackware 15 with Slackware-current kernels?

In recent months/years I use Slackware 15 on an NUC13ANKi7 server which couldn't startx, which was solved by using Slackware-current kernels. However, after kernel 6.9.10 (all newer 6.9.n and all 6.10.n) it can't boot those... I use mkinitrd_command_generator, make the initrds, but then when it boots, it says there's no initrd, despite the initrd file existing... a strange thing is, instead of GRUB putting the newer kernel at top for first choice, it has put all newer ones lower down below 6.9.10 in 'advanced options' or something. I read there was a recent Slackware-current change with kernels so it's easier to use GRUB as-is, but is perhaps the change preventing these new ones from booting with Slackware 15? I know they're not technically 'supported' but people on this forum suggested use them to be able to startx, which worked. This is okay for a time, but I just don't want to be stuck with eventually old kernels that may need security updates in future... maybe a newer 5.15 kernel has backported display support? I couldn't also install Slackware-current's GRUB because it depends on new libraries.