update - SVAG called Lotus for advice on the BMW bolts on my elise. They will complete the service, but I will be getting a "safety warning letter" from Lotus / SVAG now. I guess this is just to cover them from a legal point of view.
They also clarified, there has not been any cases of the BMW bolts "sheering off". (Not what I was told before...) Apparently, they just loosen over time easier than the stock bolts do. (like previously mentioned in this thread.)