ThisExactly during the Revolutionary Republic Regime and during Boney they annexed. But 1748 ain't like that.
If France tried to do that they would just managed to join all of europe, which was basically what happened in 1792, 1798, 1805, 1806, 1808, 1809, 1813 and 1815, against them.
Louis wasn't just being retarded in not expanding, everyone, Spain, Prussia, Sweden, Austria, and especially Britain and the UP agreed that the one thing they did want for the Austrian Netherlands was French annexation.