first of all thanks for drone! It is just awesome.
Take the drone-runner-kube chart as example. I am able to pass environment variables like DRONE_RPC_SECRET via the extraSecretNamesForEnvFrom: section. However I still have to have them in the env: section of the yaml.
I do see some indication these environment variables may be required:
It sounds like the Helm chart needs to be adjusted to better supports sourcing these values from secrets. The Helm charts are community maintained (I have no Helm experience) so unfortunately there is not much I can do other than encourage sending a patch if you know how to solve and promise it will be evaluated quickly