External drive caddy for hot-swapping drives

I wanted an easy way to add and remove drives for cold storage backups, so I created this external drive caddy using this Hard Drive Rack. It is no long available on Amazon and has gone up in price, but you can create your own using similar methods or devices. The "base" of the device I'm using is the Hard Drive Rack, which has a board for power to plug a PSU and the fan. There will be a PCI-E powered riser board (these are usually used for crypto currency mining), to power the SAS expansion card. For extra expansion, I have a cage and backplane I pulled from an HP ML110 Gen 7, which I can plug in as needed. Here is my super professional (haha) illustration I put together:

Now I can easily swap out drives as needed. This is for my offsite backup strategy; once a month I copy my data to spare hard drives, keeping 3 different copies of the data in rotation. I try to keep it simple. I just have each drive set up as a stripe and then I SSH into TrueNAS and just copy the data directly. I plan to set up replication tasks to make this easier, and quicker since ZFS replication should be quicker than copying.