When running an aggregation in the config server, the mongo process interface is implemented as a NonShardSvrProcessInterface (LINK), not being able to target other shards. Does it make sense, in order to target other shards, it could implement ShardServerProcessInterface?. The problem is that, while executing aggregation stages in the config server, ShardingState::get(opCtx)->enabled() is set false.

It exists the possibility it is coded with this intention.