Oh I strongly beg to differ, I definitely tune my bowfishing bows and arrows, but then again I am a little more extreme into it then most, but you want the arrow coming off the bow as perfectly straight as possible when it hits the water or else it will veer off in that direction and can make deeper shots very difficult to hit. Ever wonder why your shots on some fish always appear to be right on but you still miss, that could be your answer! I bare shaft tune my bowfishing arrows the same as my hunting setups and when I shot heavie draw weight bows I did have to cut down some arrows to get them flying better, but for the most bows in the 40-60# range, full length will work well, but definitely fine tune your nock height for the best flight. I just use a arrow with the barbs removed to tune with but you can use some dock foam to shoot into with a barbed head but never shoot it into a broadhead target or you will not get it back out.
Layafletch is not needed on a bowfishing arrow as the line will keep it straight, they just cause erractic flight and do not use them. Good luck!