Well, if Garuda’s installer does what it’s supposed to do and assigns your boot drive by UUID, it really shouldn’t matter. I still think swapping before install and having the system in the planned final configuration minimizes the risk of failure.
Some background: There was a time in history where boot devices were defined by their physical port location, so if you reordered or moved drives, it was up to the user to update the boot config to align it to the new location. If the user didn’t know to do that step, the computer would fail to boot. Modern linux distros should use the drive’s unique hardware identifier to find the device, wherever it’s plugged in.
Deadjournal was (is?) such an excellent niche corner of the internet. I remember being young and having trouble connecting the site, totally my fault, but I sent them an email and the admins Cryo and SCSi personally helped me get it figured out. In hindsight I couldn’t imagine another platform taking the time.