- Circuit-configured entities can be put on top of a differently-configured entity of the same type. Blueprint placing isn't blocked, but the entity's configuration isn't changed to the one from the blueprint (the issue that post was addressing).
- Placing a blueprint of a (stack) filter inserter on top of another (stack) filter inserter, when both are configured to set their filters from the circuit network, is blocked if the existing inserter's filters happen to be different to the filters that existed when the blueprint was made.
- Placing a blueprint of a requester chest on top of another requester chest, when the chest in the blueprint is configured to get its requests from the circuit network, is always blocked no matter the configuration of the existing chest or its filters. I'm not sure why this is different from the filter inserter.
- Trying to place an entity on top of a same-type entity with mismatched circuit-related configurations should be blocked, except…
- Trying to place an entity with circuit configuration on top of a same-type entity that has never had a circuit configuration set should not be blocked, and should result in the configuration from the blueprint being applied to the entity
- Entities with any type of "set <X configuration value> from circuit network" setting should be considered identical if the circuit configuration is identical, regardless of the currently active filter, request slots, stack size, etc.
- Trying to place an entity with any type of "set <X configuration value> from circuit network" on top of a the same-type entity that has <X configuration value> manually set should be blocked, even if the entity has never had a circuit configuration