

Just wanna throw in a voice saying your setup sounds completely fine to me. Maybe it’s a bit odd but it also sounds like how I’d do it if I had storage needs that large.
My current storage needs are currently met with a 2.5" SSD connected to a raspberry pi shared with samba over WiFi though so I’m pretty sure every storage nerd in here is gonna tell me my opinion doesn’t count, take it with a grain of salt.
I haven’t used raidz but a quick search tells me it supports single-drive expansion.
Maybe reconfigure your raidz as a 2-drive system, then copy over all your data into it, and expand it back into a 3-drive system after.