Found it in the "piSerial" package! Everything working now

I managed to successfully build a new stripped down image, and have two new questions:

The revpi-factory-reset command is not present, so my mac address, serial and password is wrong. I included the revpi apt repo, but apt-file did not find the command/file. Where can I get this command? I ...

If I understand it correctly I only need to run the build_image.sh script, and can I base it on 2019-04-08-raspbian-stretch-lite ?

Hi, we have gotten a few RevPi Core 3+ that we are going to use as Greengrass Core. In other words, we only need a stripped down version of the RevPi image without all the RevPi specific software. What is the best way to achieve this? I have taken a look at some approaches:

Prepare everything in ...