Hey Artherd
The distributing sentral/block has smal pistons going back and forth inside.
If a point dosen't get grease this piston will be stopped.
Then pressure rise in the system, and the pump will give a warning, or the grease will come out of the safety valve.(next to the pump)
So the points gets it amount everytime. If it dosen't you got a leak between the sentral/block and the greasing point.(this block is near each point)
You can get systems that grease everything.(and thats the solution)
Problem on the exc is to protect the lines. The smaler the exc is, the more problematic it gets to protect the lines.
I have seen solutions where u veld on a smal angled iron and tread the tube inside, weld on a ring around the greasepoint with a hole in the side for the line and so on.
I do think they have a "smalest" size that they would recomend installing it on.
But of course this depends on the produser and the tecnical design.
Some might be worse than others.
I recomend a phone call to a dealer and discuss it with them.