[kridsdale3]

With Thunderbolt 5, once external SSD enclosures supporting it exist, there should be zero performance penalty for external vs internal storage speed, finally. Then you can built a 1PB array, if you want.

[canucker2016]

M4-based mac mini's (256GB storage) have Thunderbolt 4.

If you need/require Thunderbolt 5, you'll have to step up from $599 to $1399+ for the M4 Pro-based mac mini's.