In western Daoist scholarship A. C. Graham has divided up early Daoism into a number of different themes/threads/orientations and both the Lao Tzu and the Chuang Tzu include what Graham referred to as Yangist ideas.
In the Lao Tzu for example there is chapter 13 which (in the Robert Henricks translation of the Guodian bamboo slips version)
Therefore, with someone who values taking care of his life more than running the world,
To him we can entrust the world.
And with someone who dotes on his life as if it were the whole world,
To him we can turn over the world.
It is worth noting that this chapter is present in both the Guodian and Ma wang tui versions (these are the two earliest extant copies of the Lao Tzu).
As to the Chuang Tzu, chapters 28 to 31 are viewed as Yangist.
Chapter 28 (in the Burton Watson translation) opens with:
Yao wanted to cede the empire to Hsu Yu, but Hsu Yu refused to accept it. Then he tried to give it to Tzu-chou Chih-fu. Tzu-chou Chih-fu said, “Make me the Son of Heaven? - that would be all right, I suppose. But I happen to have a deep-seated and worrisome illness which I am just now trying to put in order. So I have no time to put the empire in order.” The empire is a thing of supreme importance, yet he would not allow it to harm his life. How much less, then, any other thing! Only he who has no use for the empire is fit to be entrusted with it.
Shun wanted to cede the empire to Tzu-chou Chih-po, but Tzu-chou Chih-po said, “I happen to have a deep-seated and worrisome illness which I am just now trying to put in order. So I have no time to put the empire in order.” The empire is a great vessel, yet he would not exchange his life for it. This is how the possessor of the Way differs from the vulgar man.
Shun tried to cede the empire to Shan Ch’uan, but Shan Ch’uan said, “I stand in the midst of space and time. Winter days I dress in skins and furs, summer days, in vine-cloth and hemp. In spring I plow and plant - this gives my body the labor and exercise it needs; in fall I harvest and store away - this gives my form the leisure and sustenance it needs. When the sun comes up, I work; when the sun goes down, I rest. I wander free and easy between heaven and earth, and my mind has found all that it could wish for. What use would I have for the empire? What a pity that you don’t understand me!” In the end he would not accept, but went away, entering deep into the mountains, and no one ever knew where he had gone.
Shun wanted to cede the empire to his friend, the farmer of Stone Door. The farmer of Stone Door said, “Such vigor and vitality you have, My Lord! You are a gentleman of perseverance and strength!” Then, surmising that Shun’s virtue would hardly amount to very much, he lifted his wife upon his back, took his son by the hand, and disappeared among the islands of the sea, never to return to the end of his days.
Laying aside all the scholar talk and old texts, on a personal level I find that chapter and the whole of the Lieh Tzu to be charming, a joy to read and Daoism that is really useful to my life.
One of the things that really makes Daoism different, at least in my eyes, from the rest of the worlds religions is the Daoist focus on the physical, your physical body, this physical world and the idea you ought to aim for physical wellbeing first and then worry about other things. While I personally do not subscribe to a “pure Yangist” ethic, I do very much see the wisdom of it and its correctness in many situations.