The folks at SparkyLinux's forum would be the authorities on configuring their boot loader, but here is my opinion:
Assuming GRUB, a quick and dirty hack/test is to edit /boot/grub/grub.cfg (from within SparkyLinux).
Find the code block for VL, and the line
linux /boot/linux root=/dev/sdX (where X is the partition that VL is installed to),
and append " 4", so it becomes
linux /boot/linux root=/dev/sdX 4
The above edit is frowned upon by GRUB devs. It will be overwritten by subsequent updates to GRUB.
When you have the syntax right, the proper way is to edit /etc/grub.d/41-custom (or similar), and add the code block for VL to that script.