hi!
The environment variables can be changed at any time.
However, the configurations that are bound to the collection may or may not be mutable.
We host a list of mutable collection properties here:
If you want to change a configuration that is not mutable, you will need to reindex or data, meaning copying it over to a new collection in the same cluster or on a new cluster.
Here we have a migration guide for that:
Let me know if that helps!