Upgrading from HDD+Optane

My Lenovo Thinkpad T580 came with a 500GB HDD + 16GB Intel Optane module out of the box. I’m looking to upgrade my storage read/write speeds, and replacing only my HDD with an SSD would achieve that. However, I know that using Optane with a SSD offers very little benefit, so is there a better use for the M.2 PCIe port the Optane module is using rather than just leaving it there when I upgrade to an SSD? Would it be better to instead replace the Optane with a PCIe SSD and use the existing HDD for a RAID 0/1 configuration?