Great question. Yes, the smaller charging systems such as a bike do work much better with lithium. LiFePo4 is capable of being pushed to 14.7V-14.8V for short durations, and small C rates(amps vs capacity). As long as the voltage is less then 14.6V for the bulk of the time, it isn’t a big problem for the cell.
The smaller powersports lithium batteries BMS have a higher voltage cutoff point than a deep cycle lithium battery. They typically don’t cutoff the charge unless it gets above 15.0V.
This method works for applications with small charging systems, and small Ah capacity batteries. The problems start when the stator or alternator charges too fast, and you get a cell that “runs” above the rest, and the BMS shuts down the battery. Manufacturers are getting smarter though, and are using BMS designs that don’t shut off the battery completely for overvoltage, they just cutoff charging.
The biggest problem with lithium and alternators is when you try to use a lithium battery designed for deep cycle in a starting application. Lithium has near zero resistance, and the alternator will go to 100% load. When the BMS suddenly cuts off charging, the alternator has nowhere to dump the excess current, and the system voltage spikes, sometimes in the 30V+ range. This nukes the regulator, and also can damage system electronics.
In the next year you will start seeing better solutions for starting batteries, but for now I am hesitant to use them on expensive alternators. It can definitely be done, but by no means is it a standardized system.