How come with manual transfer payments don't hit the destination bank account in 180 seconds?

With the manual bank transfer, this doesn't happen automatically, but payments under 25,000 AED are eligible for going through the IPI instant rails.

Lean ensures in the backend that the right settings are selected for payments to make them near-instant, whenever this is possible. 

Payments over 25,000 AED are not eligible for IPI but are sent via UAE FTS payment rails. The transfer takes up to 48 hours and will only be queued and process during the bank's business hours.