Completed upgrading the 12 x 8TB HDDs in our server, Gannet (Synology RS3618XS), to 12 x 16TB HDDs. The process was simple, but the repair process took ~20hrs for each new drive. So, the entire process required 12 separate days of pulling out one old HDD, replacing with a new HDD, and initiating the repair process in the Synology web interface.
But, it’s done and we now have a total of 145 TB (!!!), with ~72TB remaining to use up!