Sorry but I couldn't disagree more with you about the use of the tool.
What you says is correct about some air needed, BUT you get that by bleeding the losi/assoc shocks like the manual says.
99.9% of the time some bubbles are trapped in the oil, yes you could tap on the shock and wait hours for them to rise but some of the tiny ones will still stick to the body or threads inside the shock. You can use the tool to quickly pump these out. I have built and rebuilt hundreds of shocks and you would be amazed at how much air actually gets in there.
The proper amount of oil will be removed by bleeding the shock correctly. If you leave extra bubbles in the oil without getting them all out by use of the air removal tool then you will have too much air in the shock to begin with. So you are basically starting with a shock that has leaked and needs to be rebuilt or one that needs to be rebuilt much quicker.
It is simply impossible to remove to much air from the oil before the shock is assemble. You want 100% of the air out of the oil before assembly. That is the exact purpose of the tool. Then by following the directions you bleed the correct amount of oil for the shock to work properly. Since I have started using the tool all of my shocks are better.
I too use the Losi shock tool, its great.