On top of that, it's enough to assert the microcontroller's reset to then freely use the RX/TX pins from the FTDI as if it wasn't there.

Just plain insanity.

As for cp2104 usb to ttl serial, full adapters using that chip cost $2 a pop on AliExpress.

As the prices are like that, I ordered a few of every available usb-serial chip at some point. I'll be fine for a long time.

Or you know, pop the Atmega out

Yeah I was really questioning the point of removing it from a board where it has all the connections it needs in order to then make all those connections again! It’s a very nice write up but I was just left wondering “whyyy?”

Indeed - I know I could have also popped out the DIP micro on the board and used it directly, but I choose not to for two reasons:

1. Its so much bulkier, and I wanted something that was the same form factor as my old unit 2. It seemed way more fun to do things this way, and I was pretty sure I could do the whole operation in less than an hour

Clearly you should have compromised and hacksaw'ed out the usb jack + ftdi region of the board, thus satisfying both your desire to have something jankey and compact. You would even get free activity LEDs!

He's not using the Arduino Uno for anything useful, its just a test jig to check the cable works. He says at the start of the article that he needs a USB-UART converter to work with another project.

I'm assuming that project doesn't have its own USB-UART like an Uno.

As the comments above mentioned he could have left the FTDI chip on the arduino board and just used it that way. Moving it to the breakout board didn’t do anything but save some space