Well it certainly doesn’t
Well it certainly doesn’t sound very sensible whether you do it in a car or on a bike, you are putting yourself and other road users at risk – particularly when you are in a car (two vehicles travelling towards each other at speed with neither driver able to see properly doesn’t sound like a good idea – particularly if there’s a vulnerable road user stuck in between them, on a bike perhaps.) X( X(
The tricky part on a bike it seems to me is being able to dip your lights quickly enough not to dazzle oncoming traffic, particularly if your main beam is on a helmet mounted torch. 😕