So before I started selling on @Tindie , I was sending off a kit to @ɖҿϝիɟթվ  and I forgot to send him a crystal with that kit / check all the content before sending. There are also two fully assembled versions out there now, one has an ESP chip with 2MB flash instead of 4MB. From then on every ESP12 module is checked before sending. 

So here's rule number one:

Use the checklist and check if every part is in the kit. Obviously.

Known issues number one is the enable pin of the power regulator is floating, you need to botch the 10k to the switch. 

I will modify all future / rest of the pcbs so it's clear where to put it

• missing markings for RGB LEDs, the dot points towards the USB plug
• the charging indicator LED - minus points towards the USB plug
• power muxing chip pin 1 points AWAY from USB plug

There is no test program that greats you with a "hooray, you've made it". 

flash the ESP with a basic code, flash RGB lights, check buttons and display

Change the I2C address of the attiny before shipping

to be continued...