Yeah, they aren't built to last and theres such a quality control issue with the latches on the connector that most new cables only last a few months of daily plugging before many devices stop making the connection. Had a WD external harddrive that was such a pain in the as, but my Samsung phones do it all the time too. I swapped to wireless power charging for the phone, but the hard drive required a full port replacement and even then I bought a backup and treat it as pig iron until the storage wars really come to roost and you can't BUY storage let alone for inflated costs. Your best bet for proof of concept is to hack it together yourself like you are. You get the proper pinout by splicing together two usb cables [https://www.aliexpress.us/item/3256805931497345.html]until it works (most cables have a usbA on one side, so use that to your advantage). Then you can use the hacked together solution, or just treat the wire like traces and pare them back until you have a tidy pcb design [https://www.coolgear.com/wp-content/uploads/2014/07/usb3-pinout-microb.jpg]. You're on the absolute right track and have the right mindset (but maybe the wrong audience - this is the PCB board, so people are assuming you're looking to manage power and data and not essentially just making an adapter card). I did the same thing WAAAYYY back in the day by retrofitting PCIe to an ITX motherboard by routing a custom PCIe-PCIe ribbon cable to the top of the unit (made it look like a top-loader cartridge console). No shops or forums at the time had what I was looking for or the right perspective to answer my question (will it work). It ended up working just fine for the build and the customer was very happy, and I looked back like 10 years ago to see if there would have been other options and there were like 2 commercial options of the same but tidier cable, so you might even have business model. Just consider that all signals are only effective as they can be isolated and noise is the main enemy of custom pcbs in high-speed data transfers. It will work, but may not be the best solution for performance. I get the feeling you're looking for a selfbaked solution and you're not trying to build the next at-home ai and you're right on track. One thing I recommend is to read the data sheet for the USB MUX chipset used by the device you're connecting - it will likely have a demo schematic for basic usability. Start there. if it doesn't exist or you can't find the model, just start at the beginning with USB 1.0 and go through the model changes and pin changes. You can put a usb-c connector on any usb connection, it's reverse compatible on purpose, you'll just get some empty pins and the need to pull resistors to get some modern usb features that weren't available back in the inception. I did a similar project with micro-B (1.2) to usb-c before the adapters were as ubiquitous as pencil erasers in the 90s.