It makes a huge difference, if you make construction time lapses or other long term timelapses (in that case I agree with you, A is okay most of the time) or if you shoot Landscapes and rather "photographic" and artistic time lapses. In that case A will introduce flicker where you need real smooth results.

For the artistic/photographic works that most of the LRTimelapse users do (however LRTimelapse has great features for construction and long-term time lapses as well) - the M mode combined with the holy grail approach (watch my tutorials) is the way to go since it gives the best and smoothest results. That's what most of the time lapse photographers want.