The phrase "an avid proponent" is correct and usable in written English.
It can be used to describe someone who is very enthusiastic and supportive of a particular idea, cause, or policy.
Example: "As an avid proponent of renewable energy, she dedicates her time to advocating for sustainable practices."
Alternatives: "a passionate supporter" or "a strong advocate".
At the same time Mr Davutoglu is an avid proponent of Turkey's membership of the EU.
Mr. Hickel returned to Alaska, reinvigorated his business empire and again, as an avid proponent of development, began an ultimately successful bid to return to the governorship.
He moved to New Zealand after a biological classification system of which he was an avid proponent fell out of favour.
German educator Friedrich Froebel (1782 1852), inventor of the kindergarten, was an avid proponent of paper folding and its educational benefits, and he helped to spread paper folding around the world.
She mentioned, in an unhappy manner, former Prime Minister Bertie Ahern, an avid proponent of the treaty and currently the subject of an inquiry into financial irregularities from the 1990s.
He fished extensively aboard the "Sandra T" in South Florida, the Bahamas, Mexico, and the Virgin Islands and was an avid proponent of tag and release programs and marine conservation.
"Steve of everyone I've known in life could be the most avid proponent of some position and within minutes or days if new information came up you would think he'd never, ever thought that," he added.
"Not even the most avid proponents argue it is.
Mr. Mooney, an avid hiker and animal rights proponent, plays down the commitment, saying he is not an environmental expert and has not found all the eco-friendly options.
Moby, an avid environmentalist and early public proponent of veganism, was among the 19.5 million YouTube viewers mesmerized by Cutts' work.
She has been an avid supporter of welcoming refugees, and a longtime proponent of LGBT rights.
