Reddit mentions of Goliton USB 3.1 Front Panel Header to USB 3.0 20Pin Header Extension Cable 20cm for ASUS Motherboard

This might be convoluted, but to adapt usb 3.1 to usb 2.0, could you use two different adapters? Like, 3.1->3.0 and then 3.0->2.0?
Maybe a combination of these cords?

https://www.amazon.com/Adapter-Converter-convertor-Motherboard-Gigabyte/dp/B07L9RWRMM/ref=sr_1_4?keywords=usb+2.0+to+usb+3.0&qid=1572354854&sr=8-4

https://www.amazon.com/Goliton-Front-Header-Extension-Motherboard/dp/B078Y2JNXN/ref=sr_1_3?keywords=usb+3.1+to+usb+3.0&qid=1572354770&sr=8-3

I think you're talking about this?

https://smile.amazon.com/Goliton-Front-Header-Extension-Motherboard/dp/B078Y2JNXN/ref=sr_1_8?keywords=usb+c+header&qid=1571246992&s=electronics&sr=1-8

If I buy that SilverStone CP14, that allows me to convert from the 19-pin header to the new 20-pin Key A standard which supports (from my research) a single USB-C output or two USB-A outputs, is that correct? But is that CP14 converter limited to 5 Gbps speeds regardless, because the 19-pin connector is only meant to support 3.0/3.1 Gen 1? Or does it magically pair together the two 5 Gbps lines intended for separate USB-A connectors into a single 10 Gbps (3.2 Gen 2) USB-C output?

How is that different from this?

My new PC build is a small form factor case with a Mini-ITX motherboard. So there is only one PCIe slot and no space on the back for a PCIe card besides the GPU. (There happens to be a small plate above the GPU which I plan to replace with a 3D printed part with USB-C output(s) though). So (besides maybe my extra M.2 slot) there is only the 19-pin header that I can use to provide me with USB connectivity (aside from the slow USB 2.0 header, which I'm happy to ignore entirely). So I won't be able to use your suggestion for the second two links in your comment.

But my question, now, is whether I should buy that CP14 converter or another single-USB-C-port converter like FIGURE 2 or just build my own two-USB-C-port adapter from FIGURE A + 2x FIGURE C. The CP14 converter might give me 10 Gbps, FIGURE B will give 5 Gbps, and the combination will give two 5 Gbps ports. Is there anything else I am missing before I decide whether it's worth having two 5 Gbps ports instead of one 10 Gbps port?

Also, I cannot actually find anywhere to buy the CP14 product, it looks like it is not out yet. But does this product work just as well?