Can I install the bootloader to /boot instead of the MBR/UEFI?

I cant really afford to lose my windows partition now – normally if there was nothing important on it I could install linux first then windows again over it to avoid UEFI boot issues with it not letting me back into windows…

but I have literally terrabytes of data I cant lose.

Debian in advanced mode would let me do it, and gentoo would too on the regular completely custom install. is there any way your installer can be overridden so I just write the bootloader onto another hard drive so that way the UEFI bootloader doesnt even see it unless I hit F3/4/whatever to boot from that hard disk manually (i.e. leave current boot order alone, install a bootloader that has to be manually chosen at startup so Grub ONLY starts if you select to boot from that disk via bios/uefi at startup manually)|

it would just avoid a lot of problems for me and completely bypass any UEFI issues.

Im fairly positive if I install onto a portion of the disk and let grub take over, when I try to boot windows it will just tell me there is an error until I repair the boot sector back to the way it was. its whats happened to me ever since UEFI started.

Id really rather have BIOS back.