Beaunoir served Nicolet until 1780, then composed more ambitious plays which were given at the Théâtre des Variétés-Amusantes and the Comédie Italienne.
Around 1770, he had become King Louis XV's librarian, but his reputation as a libertine author undermined the dignity of his colleagues who demanded in 1783 that he write anonymously.
Repudiated by van der Noot, he wrote his "historical drama" Histoire secrète et anecdotique de l'Insurrection belgique, ou Vander-Noot (1790), scandalous pamphlet in which he denounced the failures of revolutionaries.
In search for a shelter from the wrath of the tyrant he described, Beaunoir fled to Holland where he wrote another satire, Les Masques arrachés which rapidly spread in Belgium and lead to the fall of van der Noot.
Leaving the Netherlands, Beaunoir went to Neuwied and joined a colony of French men of letters, including Louis-François Metra who had him collaborate to his Correspondance littéraire secrète [fr].