Keeping up-to-date with FreeNAS/TrueNAS is no different to keeping up-to-date with your desktop OS. If you wish to stay up-to-date with security, bug fixes and features then updating is the obvious choice. If not then…
There’s one important difference–older-than-current versions of TrueNAS become unsupported much more quickly than older-than-current versions of macOS or Windows. Windows 11 was released over three years ago, and MS is still patching Windows 10 (though that’s apparently about to end). But iX isn’t touching CORE 12, much less FreeNAS.
If your server is not exposed to the internet, will that make a real difference? I’m sure i am overlooking simething but it it works, why break it? But like I said maybe i am missing something that I should see.
Flip phones tend to remain charged a LOT longer than a smartphone. I like that aspect, and they are more difficult to accidentally damage. Oh yes, they cost less too. Hum… $150 flip phone or $1500 smartphone.