I would heavily suggest not doing this. HDDs are significantly more reliable than flash storage when it comes to long-term, power-off data retention. Period. There’s a relatively little-known fact about SSDs and flash storage where they aren’t actually rated to sit around with data on them for all that long. The voltages stored inside of them degrade and the data is slowly lost over time if they aren’t powered on. The enterprise SSDs that I work on are rated for 3 months - as in, set it on a shelf for three months, and after that, if you don’t power it on, it isn’t guaranteed that all of your data will still be there. And this is talking about ultra-redundant, enterprise SAS SSDs. MicroSDs don’t have any of that redundancy. (And yes - this implies that setting a bunch of important flash drives in a safe for ten years is not a great idea. That is true! It’s unlikely that you will experience data loss, but it’s more likely than with an HDD)
That’s actually a surprisingly powerful SBC for what it costs. Does Pine64 stuff come with fancy looking enclosures like that one, too?