log_level → DEFGUARD_LOG_LEVEL -> Env variable
log_file → DEFGUARD_LOG_FILE -> Env variable
auth_cookie_timeout → DEFGUARD_AUTH_COOKIE_TIMEOUT -> General -> Instance
secret_key → DEFGUARD_SECRET_KEY -> Not in settings UI
database_host → DEFGUARD_DB_HOST -> Env variable
database_port → DEFGUARD_DB_PORT -> Env variable
database_name → DEFGUARD_DB_NAME -> Env variable
database_user → DEFGUARD_DB_USER -> Env variable
database_password → DEFGUARD_DB_PASSWORD -> Env variable
http_port → DEFGUARD_HTTP_PORT -> Env variable
grpc_port → DEFGUARD_GRPC_PORT -> Env variable
grpc_ca → DEFGUARD_GRPC_CA -> N/A
grpc_cert → DEFGUARD_GRPC_CERT -> N/A
grpc_key → DEFGUARD_GRPC_KEY -> N/A
default_admin_password → DEFGUARD_DEFAULT_ADMIN_PASSWORD -> N/A
openid_signing_key → DEFGUARD_OPENID_KEY -> Not in settings UI
webauthn_rp_id → DEFGUARD_WEBAUTHN_RP_ID -> Not in settings UI
grpc_url → DEFGUARD_GRPC_URL -> Remove
disable_stats_purge → DEFGUARD_DISABLE_STATS_PURGE -> General -> VPN stats
stats_purge_frequency → DEFGUARD_STATS_PURGE_FREQUENCY -> General -> VPN stats
stats_purge_threshold → DEFGUARD_STATS_PURGE_THRESHOLD -> General -> VPN stats
enrollment_token_timeout → DEFGUARD_ENROLLMENT_TOKEN_TIMEOUT -> General -> Enrollment
password_reset_token_timeout → DEFGUARD_PASSWORD_RESET_TOKEN_TIMEOUT -> General -> Enrollment
enrollment_session_timeout → DEFGUARD_ENROLLMENT_SESSION_TIMEOUT -> General -> Enrollment
password_reset_session_timeout → DEFGUARD_PASSWORD_RESET_SESSION_TIMEOUT -> General -> Enrollment
cookie_domain → DEFGUARD_COOKIE_DOMAIN -> Env variable
cookie_insecure → DEFGUARD_COOKIE_INSECURE -> Env variable
proxy_grpc_ca → DEFGUARD_PROXY_GRPC_CA -> N/A
check_period → DEFGUARD_CHECK_PERIOD -> Env variable
check_period_no_license → DEFGUARD_CHECK_PERIOD_NO_LICENSE -> Env variable
check_period_renewal_window → DEFGUARD_CHECK_RENEWAL_WINDOW -> Env variable
http_bind_address → DEFGUARD_HTTP_BIND_ADDRESS -> Env variable
grpc_bind_address → DEFGUARD_GRPC_BIND_ADDRESS -> Env variable

Add an info box next to settings that require Core restart.