I'm sure there are threads about acclimation here on RC ... IMO/E after a short temperature acclimation (sealed shipping bag in tank/sump) and then about 15 minute drip, fish can go right in without problem. If the fish are going into a QT with salinity matched to shipping bag, then no drip is necessary.
The longer the fish has been in shipping bag, the more dangerous/stressful the long drip time can be.