How plausible is a six-limbed flying animal roughly the size of hatzegopteryx to be aerial? In this case, an aerial animal will be defined as a creature that solely inhabits the sky. I will call the animal a dragon for simplicity.
The creature spends its entire life gliding through the air. The only time it spends on land is when it hatches and when it lays its eggs. At the end of these creatures' life, they meet with another dragon and engages in a fantastic mid-air mating display. Once the female has been fertilized she will seek out a suitable cliff or mountain. The cliff or mountain must be at a perfect altitude: high enough to jump off of and glide, and low enough so that there is suitable oxygen. Once the female finds a perfect location she will memorize it and begin a new search. The female will then spend the next few weeks collecting Tree-toppers, a fruit-like mass that grows at the peak of tree-like plants. Once the female has collected a sufficient amount and placed them at her nesting site, she lands above her nest and lays five to six eggs. Once the female has landed, she will never fly again. She spends her last few months of life caring for the eggs until they hatch. At which point she will wait for them to build their strength. Once the dragon hatchlings are strong and large enough to collect Tree-Toppers for themselves, they leap from their nest. These young dragons will spend the rest of their lives gliding through the air until they sense their imminent mortality, at which point the cycle repeats.
How plausible is it for this animal and its lifestyle to exist?