DOMAIN=spencerslab.duckdns.org - This env is used all over the place. Traefik uses $DOMAIN to generate the service URLs and tries to get TLS certificates through Lets Encrypt. There are also a number of services that use $DOMAIN to generate URLs for links within the service.
LIVE_MOUNT_<SERVICE_NAME>_<MOUNT_DIR>ENABLED=true to enable a mount used to present files from the given service to the host OS. Live mounts can usually be found at technocore/data/
DEV_MOUNT_<SERVICE_NAME>_<MOUNT_DIR>ENABLED=true to enable a mount for the provided service that will aid in development. Mounted volumes can usually be found in technocore/services/
STACK_NAME=technocore - Allows you to set the swarm stack name.