HaLeiVi -“Health, but as I wrote earlier, being Mekabel Shabbos is treated like a Nedder.”
But my point is saying Good Shabbos is Not being Mekabel Shabbos, nor is it a Loshon of Neder. People think by using fancy Jewish terms they can fool others into thinking that this is a Halacha or some Chumra based on Halacha. Unless you say it’s some sort of Maaris Ayin -I see no basis for this “Chumra”.