It is true that MSS has always required getting a voucher from the B Connected booth prior to going to the cashier. We learned the hard way many years back after waiting 25 minutes in the buffet line then having the cashier tell us to go back to the players club. Knowing this before you go will help the process go smoothly, only takes them a couple minutes to write up the voucher. Feel free to use B Connected points for the second meal and it won't cost you a thing for a very good buffet with a nice atmosphere.
The Fremont is another buffet that may require you to go to the players club for a voucher. This facility has been inconsistent in its policy over the years, sometimes they will take the coupon at the cashier, other times they make you go to the B Connected booth. We now automatically go to the players club first to ask. Heck, it's right on the way to the buffet.