i would like to point out that right now its possible to queue movements, by selecting the next actor and giving him an order and it will execute and it saves a lots of time during the deployment phase (first few turns) , so please lets avoid the technical solution of disabling this feature.
also, i would like to stress that mostly it shows the amount of TU's or at least i never noticed that i actually lost TU's, with the only exception, when one wide square path involved, soldier may take the scenic route around when fat clicking.
If a player selects a 2nd actor while the 1st is still moving, he probably does that to figure out where to send the 2nd to. Even with the suggested fix, the TUs displayed for the 2nd actor are wrong while the 1st is still moving.
no, usually in combat with RF reservation, positioning and shooting in mind, i dont have enough Time to select my next actor for this to be a problem, on the other hand during the deployment phase, there is no thinking or planing, i already played this map and i know exactly where my soldiers are heading and i am trying to get there as fast as possible.
which why i mentioned the one square wide path's, i prefer not to but dont care if i had to fast click once more to exhaust my TU's, because at this stage i dont even look at them, i just fast clicking toward a general direction but i do care if my soldier runs on a detour or i have to start re selecting soldiers until pathfinder updates (or if one of them eneds his turn in that spot but this case is unrelated).
EDIT:
so to sum it up, lets wait on cutting down features, if there is a possible solution great if not lets try to avoid the problem in the first place.