The time "wasted" and then added on is not the problem. The problem is players deliberately stopping the game for as long as possible to interrupt the momentum of the opposing team. The longer the delays, the more difficult it is for the opposing side to reach the previous momentum.
I doubt any form of timekeeping will stop the "time-wasting" as it is called. Managers and players will always find a way round that.
I would just like it to be referred properly as to what it is.......which is cheating.
Slow ambling off the pitch with late substitutions , goalkeepers taking...