There's always a learning curve. Yes, it is a pain point and happens all the time. But there are ways to mitigate and make it more productive. I just happened to be on a KT today with my developers (one developer KT'ing to 3 others) and it went quite well. The biggest mistake I see is going straight to the code before understanding the business features, purpose and rationale it was done that wa, in this order.
Will be happy to go on a call and discuss further.