It’s worth noting that M.2 & U.2 both have 4 lanes, so anything more would need to be HHHL or FHHL. Anyway, the Liqid LQD4500 has a 4.0 x16 interface and claims

It’s worth noting that M.2 & U.2 both have 4 lanes, so anything more would need to be HHHL or FHHL. Anyway, the Liqid LQD4500 has a 4.0 x16 interface and claims 24 GB/s. I don’t wanna know how much it costs, though. https://www.liqid.com/products/composable-storage/element-lqd4500-pcie-aic-ssd https://www.liqid.com/products/composable-storage/element-lq... https://www.servethehome.com/liqid-element-lqd4500-32tb-pcie-gen4-x16-nvme-ssd-oss/ https://www.servethehome.com/liqid-element-lqd4500-32tb-pcie...