TERES-USB-DEBUG cable is now in stock. TERES has unique features to multiplex audio port between audio headphone output and serial console debug.
There are two ways to enable the serial debug via audio jack. First one is with teres1-debug on|off script and it will work until reboot:
sudo teres1-debug on
when you want to stop use
sudo teres1-debug off
this is good for try something while your laptop is working, but if you want to catch the early uboot messages you have to use another script:
sudo debug-switch.sh on
this will switch debug serial port permanently to audio jack until you execute the scriupt
sudo debug-switch.sh off
These scripts are included in the official image, but if you build your own you can install them from the GitHub sources
olimex 
Mar 15, 2018 @ 16:50:58
Are there any non-english layout keyboards available?
Mar 17, 2018 @ 09:20:07
I don’t think this feature is unique – Motorola C123 (and lots of other mobile phones) had serial-over-headphones communication back in the 2006.
Mar 17, 2018 @ 18:36:00
Even though it’s offtopic, but there are about 1200€ missing from the Bootlin Kickstarter campaign for the video decoding of h265. If anyone has a couple of bucks to spare go here: https://www.kickstarter.com/projects/bootlin/allwinner-vpu-support-in-the-official-linux-kernel