I saw this Gif video on a Polish ebay seller.
It showed a LDA in action. With much in Polish I got some of it translated.
I added in some labels and took off the animation for clarity.
Here it is with partial foot feed and no boost.
Notice that the foot feed and fuel being delivered are in proportion although there are no quantities are defined.
As the boost starts to come up. The pressure pushes the pin down against the spring and the Boost pin goes down the follower pin can slide in more. The follower pin is connected to the main fuel system with a lever.
There is an increase in fuel being delivered compared to the foot feed.
Here it is with the LDA fully engaged at the high boost level.
Definitely more fuel as the cone is now touching the follower pin at the narrowest part.
This is a hard part to analyze with springs pushing an unknown quantity Maybe smoke is the best that one can do for analysis.
I think pin travel might best be monitored with a pressure gauge and small pump. Put 5 psi or ten and then look at the travel of the boost pin against the follower pin. That still doesn't say how much fuel is being delivered.
Want my motor to use the least amount of fuel which should be good for it and only have higher fueling when it is needed. If added fuel causes heat at least for a while then having it lean as much as possible sounds good.
I really like the quality of the stock components and have never had a vehicle last as long except perhaps our 85 Mercedes.