For anyone interested, I took delivery of the new Corsair EX400U external SSD today, which claims data speeds of up to 4,000MB/sec sequential read and up to 3,600MB/sec sequential write. I don't need oodles of space, so opted for the 1TB model. Using it on a MBP M4 Pro 14, I formatted it APFS and tested it on Blackmagic Disk Speed Test. Results were good, but not what I had hoped for:
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