The issues that come up are when you have a headwind on the outbound (happens with kiwi wx sometimes) therefore after you reach the time you can turn inbound before the FAF. Bugger, missed approach time One also cant time adjust when indicating over 110kts
Same thing happened with Bathurst NDB approach here in Oz.
The only thing to do is, go like you stole it on the outbound leg for the maximum allowable time and bring the speed back to the minimum safe on the inbound.