Detective Chief Inspector Gus Viera on Thursday said he wasn't a fan of music festivals and wanted police to have the power to close festivals early when public safety is at risk.

He told the NSW Coroners Court he also wants the hours of festivals restricted to no more than eight hours in a single day, saying "marathon events" running 12 hours give too much time for young people to overheat and ingest prohibited drugs.

"It's all bad," he told the inquest into MDMA-related deaths at music festivals.

"As a father to two daughters, I wouldn't let them go. So no, I'm not a fan at all."

Det Chief Insp Viera was the police commander at 10-hour dance party Knockout Circuz in December 2017, when Sydney man Nathan Tran consumed multiple MDMA capsules and died.

Shortly after Mr Tran arrived at the medical tent about 10.30pm, the event's private medical provider said they were incapable of treating further "walk-ups", Det Chief Insp Viera said.

The officer said he took "walk-ups" to mean drug overdoses.

He said the possibility of ending the event was raised before its 12am close, but the event organiser and the ambulance supervisor argued that it was nearly over and shutting the event at that moment could place pressure on nearby hospitals.

At the inquest, he agreed early closure in that instance could have created more harm and it was the right decision to keep it going.

The senior officer said he also wants events to be forced to light hallways and other areas between stages to assist in locating ill people.

"Police and roaming ambulance personnel can't identify anyone who is in trouble," he said.

"It's impossible to see if anyone is unconscious."

The inquest was told police designated their operation at Knockout Circuz with a colloquial term for inferior music: "clinker".

Det Chief Insp Viera said he was unaware of the word's colloquial meaning, adding he doesn't have the power to assign names and "shudders" at some operation names.

Australian Associated Press