Build a ramp on the side of the platform saddle and park an anky on the edge of the ramp. Fly to your favorite metal node farming spot with your tribe and let them just swing away. The anky's weight doesn't affect the quetz's weight.
The fun way is to jump off and grapple to your argie and whistle it to attack and since argies are slow it won’t catch up in time so tranq till it goes out also bring parachutes and consider liking so more people will know
If you drop a quetzal due to knockout, and it lands next to a giga...just know, the quetzal belong to the giga. Now you get to watch your would be quetzal get eaten by a giga. Now you can go home and cry.
If you manage to knock a quetzal out, try starve taming. If you never tried starve taming it’s just leaving a Dino’s hunger go to half way or lower and then you start feeding. I’ve done this many times and it’s very useful taming trick.
I know this is pretty common knowledge, but for the guys who always find the quetzal they're trying to tame in an area loaded with sabertooths, carnos, and rexes, all quetzals that are frightened will fly towards the coordinates 50, 50, every single time.