I found one of the greatest problems with the BMW system was the wear associated with the mechanical advance system within the stock beancan, and the fact that a failed Hall Effect sensor meant you were off the road. One could carry a spare bean can, but that is bulky, one could fit an additional Hall Effect sensor to a stock BMW beancan but that would leave you with the mechanical advance system.
Make my own system with a true electronic advance within the ignition module.
Fit a twin plug system that is fully redundant running separate coils. So now if a Hall Effect fails, change over the plug to the spare, a failed coil will not stop me as the redundant system takes over, and carring a spare ignition module is an easy solution should that fail.