P.S. If I could, I'd totally update the OP to reflect the current version of the project XD
Time for a long-overdue project update. Omitting a lot of steps/details here, for relative brevity. A friend of mine, from Discord (the same one who was kind enough to help me troubleshoot the many of the issues I encountered), had me run a Linux LiveCD on the server to troubleshoot the LSI HBA. For those of you who did not know, the LSI HBA wasn’t working as expected until a few hours ago (late last night). I tested it in my current workstation (Precision T7500 - Windows 10), the server (DL580 G7 – ESXi 6.5u3), and even on my laptop (EliteBook 8770w - Windows 10). When tested on the T7500, the HBA showed up – but none of the 4TB hard drives showed up. The same for the laptop and the server. After a bit of Googling (as the cool kids say), I decided that it may behoove me to try flashing it with the IT firmware, to see if that would fix it. I did so from my laptop, by making use of a powered PCIe dock (to prevent further downtime on the T7500 – running a Minecraft server). I did so, using a GUI application called MegaRAID Storage Manager. The HBA was on v17.X, and now it's on v20.X. The drives also appeared in Windows Device Manager for once. However, they didn't stay in Device Manager for long. They popped in and out, sporadically. I was instructed to reboot after the firmware update was applied. MegaRAID Storage Manager stopped being able to connect to the local server after the reboot it said to do, for the firmware update to take hold. That meant that, if the firmware I flashed was the wrong one, I’d have to resort to using sas2flash. After no luck checking on the HBA from my laptop, I decided to put it in the server, with the Linux LiveCD (as mentioned earlier). The Linux LiveCD was running an older build of Manjaro, and managed to see all of the drives in gparted. However, we were unable to get SMART data for most of the HDDs. If you look closely at the HDD models, you may or may not be able to tell why. However, while I was in the LiveCD, I decided to also try GPT scheming the Intel SSD as well, since messing with it in Windows simply did not work for some reason. A short while later, we tried the latest Manjaro LiveCD available (because Manjaro is my preferred distro with sysemd). That one didn’t see the drives at all, but did still see the HBA. At this point, I saw no other way to validate the HDDs further. I made the decision to test them in ESXi and try to pull SMART data from esxcli. The drives showed up in ESXi, and even allowed for us to pull SMART data – but it was limited, in a different format than most common drives on the market. I was able to add the Intel SSD to the Virtual Flash pool for once, though. As such, this is strictly a partial victory. We have the drives ready for use, presumably. But we don’t know how the drives are doing – which is very different from all of my previous experiences, where I could pull up SMART data immediately after installing the drives. The game is afoot.