May as well use the aircon to cool the boosted air rather than the pre-turbo air.

But generally thats not used as its more efficient just not to have aircon full stop (weight and power sapping pumps mainly).

The colder the air is that goes into the turbo, the colder it is going out, increasing efficiency, effectivley moving the compressor map over a bit.

Only worthwhile way tho IMO (barring decent cold air feeds etc) is pre-comp water (or nitrous) injection.

Pre-comp water inj is more effective at dropping temps than at any other point.
Just needs to be done right to not cause damage to the compressor wheel.