How to set environmental variables for postgres?

[dreadedhamish]

I've attempted to set some additional environmental variables for the postgres container - I've got 40 cores and >160GB of RAM that I'd like to better utilise.

These are the variables I've attempted to set:
SHARED_BUFFERS: 8GB
EFFECTIVE_CACHE_SIZE: 48GB
WORK_MEM: 64MB # maybe 64MB
MAX_WORKER_PROCESSES: 20
MAX_PARALLEL_WORKERS: 20

Seting these in the docker-compose file has no effect - it still loads with the defaults.

Any hints on how to apply them?

[dreadedhamish]

Actually it looks like it might be using my settings, while the quickstart log is reporting the default settings.