Idle Transfer Slot on secondaries?

Posting here as I haven’t gotten much traction on FBBO.

Carb is a Holley 650 Double Pumper.

Does the idle circuit use the transfer slots on the secondary as well as the primary? Or are the secondary transfer slots for smoothing the transition from primary to secondaries?

Or another way to ask.

Do I need to have the transfer slots on the secondaries exposed the same way as on the primary side (just a small square)?

Thank you for taking the time to read and respond!