I don't touch FTDI boards because I can't be sure whether they have counterfeit chips on them before I buy
This is actually a fairly important point, I buy my parts from Digi-key and trust them, but how can my customers trust what I do? They can not and should not, so that is a problem. When you couple that with the fact that FTDI has managed to block the counterfeit parts from working with there drivers then you should be able to see the scope of the problem. To add to the scope I also need the USB to serial bridge to have a VID/PID that I am allowed to send to customers, but options other than FTDI don't provide that so I'm not sure what to do.
The VID/PID on USB is controlled by the USB consortium (usb.org) and acquiring my own numbers (which is the proper way to do USB) is very expensive.
I personally prefer using a hardware UART when it is available (e.g. on single board computers like the Pi). The RPUadpt has an interface for a UART that could be from a USB bridge or hardware. I should add level conversion buffers to the RPUadpt sort of like what the RPUpi has, then decide the fate of this RPUftdi board.