Well, I finally did something worth making any kind of a post about. After some fussing, I installed Void Linux on my desktop - and the problem wasn't installing the system itself. As it turns out, my EFI bootloader is a mess and Void wasn't being provided an entry in the loader. It took a bit of tinkering but I got it set up properly and now I get a nice GRUB display when I turn on my computer, which allows me to easily choose between Linux and Windows.
Here's a more detailed breakdown of what happened. Even though Void was installed on my secondary SSD it wasn't showing up when I pressed F12 to view my boot options. Given that FreeBSD had showed up previously I was a bit confused why Void wasn't showing, especially since I had a broken "ubuntu" entry listed. I believe the Ubuntu entry came from an early attempt to install 18.04 a few days after it came out, and there were issues with installing GRUB on the disk. Since I had two *nix bootloaders listed at some point or another, there was a bit of digging I had to do.
After posting on the Void Linux forums and asking around on the IRC, I was pointed toward using `efibootmgr` to list and edit boot options. When I did so, there were 8 entries - 0-indexed, so they went from BOOT0000 to BOOT0001 - but I was also getting an error. BOOT0001 wasn't readable, and I suspected that was my missing Void boot entry. After some additional directions I was told to try mounting the efivars partition of my machine, so I ran `mount -t efivarfs efivars /sys/firmware/efi/efivars` and that allowed me to list BOOT0001 properly. The only issue is that it was listed simply as "Hard Drive" - not the Void Linux that I'd been hoping for.
Now that the efivarfs was mounted I could actually make edits. I manually listed out the entry title (simply "Void"), what device and partition number the bootloader is on, and the file location of the boot loader and the listing was added to my BIOS boot menu. It was automatically set to the default which was more than fine with me, especially since GRUB automatically detected and listed my Windows boot manager as well. Now I can simply boot my computer and select what operating system I want, with Void being the default.
Now, as for the "Hard Drive" entry in my BIOS bootloader? That means that when I installed Windows 10 on my primary SSD, the bootloader got installed on my HDD that I had installed for additional storage. This means that in order to boot Windows, my computer must first check the much slower HDD for boot information, which explains a lot about why my boot times were slower than I expected, even with Windows fast boot enabled. Because of this, I'm considering a full nuke-and-repave where I backup any important data, wipe the drives entirely, and reinstall both OSes properly. Most likely Windows will go on the smaller 120 GB SSD this time given that it will have the full HDD to use for storage, and the HDD (which will probably be swapped for a faster and larger version) won't be connected until I'm sure everything has been installed properly. The 240 GB SSD will then house my Linux data, and I will add an fstab entry to mount the HDD (or a partition of it) in case more storage is needed or if I want to transfer files between the two OSes.
Either way, I'm working on perfecting my current Void setup. I'm using i3wm this time as I'm not too concerned with special function keys such as volume and display brightness as I would be with a laptop. For a while I was playing around with the Tint2 panel system but decided that the integration just wasn't going to be as easy as I wanted, whereas something like Polybar will be much easier to use. In fact, I've started browsing /r/UnixPorn on Reddit to see if someone has a configuration that I can steal. Given the current appearance of my site (which will be fixed eventually), I definitely don't seem to have the design skills to make things look nice. However, the configuration details will all go in a separate post where I actually talk about what changes I've made and what issues I've run into. I will say this - I've missed using Linux on a desktop, and can't wait to get back to my job at school.