Ok .. after tryin myself in the last few weeks in any variation on zones, powered up through lagpilebuffs, its definitly a fact, that you CANT raise your fletching skill with this arrowvariation! .. Its easy to get the girplan feathers in Korafax (as long as ya at least lvl 85 solo top gear), but its senseless anyway, because you are not able to raise the approx. droprate from 1 per 1/2 an hour MAX (!!!) in overpowered farmpower in ANY of the listed (and non-listed) zones .. I tried them ALL!!
And now i am goin to look onto different ways to possibly max my fletchingskill ... e.g. bows (yes! ... you doubt? ... LoL .. you will learn it the hard way ...)
Remember .. i warned ya to try ))