So we know Windows has a bad habit of placing the boot file on the second drive if it finds one, like if I have an SSD and an HDD as the secondary drive, it is best to disconnect the HDD to prevent Windows from placing the boot files on the second drive. But what about if that single SSD, has a C: and D: Partition, let's say I delete the C: Partition and the preceeding MBR / System partitions then create them again, will Windows place the boot files on D: or is it safe to do the installation this way?
No need to format the partition, you can install windows on D/E/F... w/o any problem. The current bootloader will be upgraded/replaced adding the new os choice. That's all