You probably don't want to use this the same way you don't want to use random Docker images from the docker hub. I don't see the use case for this.
If it helps with piece of mind, the images are built in the open (the Azure Pipelines YAML file in the repo handles this).
There are a bunch of scenarios in which you may find yourself unable to create these with debootstrap yourself (e.g. restricted permissions, a kernel without binfmt_misc suppport), but are able to use them (using proot to avoid needing admin, or Resin's patched version of QEMU that reworks execve() to operate without binfmt)