It's not a matter of whether the string stays in tune or not. If the string does not sit on the nut properly, buzzing would occur and it wouldn't be beneficial in the long run considering that major buzzing does affect your playing.
For me, that kind of buzzing is just plain irritating because it bugs the hell outta me when I'm playing. Also, the tendency of string slippage is very high.
I would suggest bringing your guitar down to a shop and have your nut filed accordingly to fit your strings. A nut file is different from your regular files and filing a nut is trickier than what most people would think.
Out of point but in a case where you decide to sell your guitar, no one is going to buy it. I mean, who would want to buy a guitar that buzzes when it is supposed to ring :/ ?