Another GK training test for my ST J. REP (I can see that he is a 2nd class fast trainer).
20 greens for this set
20 more greens for this.
I saw in his "final" set that he earned those skills only from the box-drill of "Shooting" and not any from "Wing play"
So for another time I can't see any advantage of the trick.
Also in another test, i confirmed (paying 4-5 greens for nothing), that if there is some connection loss, the "hidden" gaining of the previous GK drills is lost.
So it's very risky to spend so many greens and have some interruption before the last useful drill set.