Quetzals and any tame that can hold a gasbag can't feel the weight of a gasbag's inventory. You can put three weight gasbags on a quetzal's saddle if you build as wide as possible. If each of your hahaha can hold 10k weight, then that adds up to 30k quiet in the back of the quetzal and the quetzal won't feel any of it. Great for metal runs, fob building, and moving.
If you run out of gas and are falling to your death, right before you hit the ground, dismount, and your fly bean will be safe, and you will land on top of it. Works every time if you do it right. Also this literally works for every other creature.
Gasbags is one of the best support tames in the game. It has great weight, is tanky, and when you level up speed, it can go very fast while flying. Not to mention but they are adorable. I suggest players get gasbags on both PVP and PVE. The only drawback is it does no damage and if you aren't careful you can kill it by falling to your death.