The actual enterprise solution would be to use the slimSAS ports and/or an HBA card in the pcie slots.
That being said, I wouldn’t expect too much performance difference between pcie 4 and 5 for your use case? You would rely more on random access and probably high parallelism? An enterprise class pcie 4 drive will perform better and especially more consistent than a consumer pcie 5 one like the T705.