In all my flying, I have never done that. I feel that the space in front of a row is for people seated in that row and should not be used by people as thorough fare to go from one aisle to another. I rarely sit in the middle section of bulkhead seats, but even when I am not seated in the said bulkhead section, it irks me when I see passengers using that as if no one was seated there.
What do you think?
Sometimes they trip over some one's leg, shoes or some other item. Once a passenger tripped over my CPAP hose.

On another occasion, we were seated in business class, my wife and I in window and aisle and my kids in two bulkhead aisle seats in the middle section. The FA parked the newspaper trolley in front of their seats, making it difficult for my son to get up to go to the restroom when he needed to go. A few seconds would be OK, but I really don't think people should intrude into space being used by others. I never expected it from an FA.

It is possible to have too much leg room. If the bulkhead row has only a few inches of extra room, you are usually OK. But in bulkheaqd rows where there is 6+ inches of extra room, you will get unwanted traffic.

In exit rows, I've had FAs park carts directly in front of my seat, really making me feel penned in.

I have done it once - both aisle blocked by trolleys so only way to a nearby bathroom was through the exit row. It isn't something i'd do normally, I try to respect people's space