It may not be exactly what you asked for (ALCAR vs LCLT) but this study shows that ALCAR and PLCAR may be better different things (ALCAR for mental fatigue and PLCAR for general fatigue).
Are you arguing that ALCAR is the best/only form of carnitine to use, or only that there’s no reason to use LCLT specifically relative to ALCAR? Because if it’s the later I’ll have to do some more research. If it’s the former, then this study should be sufficient to show that ALCAR isn’t the be-alll-end-all of carnitine for every single potential use.
Not a human study (pigs), but it suggests that LCLT may be absorbed faster than ALCAR (and other forms of carntine). Perhaps this makes it better suited for workout/recovery purposes (which the vast majority of carnitine studies focusing on this use LCLT not ALCAR for)?