That would reduce the playing strength of teams and possibly fall outside of Euro employment laws. Supporters want to see their team play their best players irrespective of nationality.
It was suggested, some years ago, a time keeper and the clock stopped every time that play stopped or the ball went out of play but it was decided that a 90 minute game would take about 2.5 hours as now the average time the ball is in play is about 55 - 60 mins.
For 10 mins instead of or as well as yellow cards. Engage a time keeper and copy rugby that the game finishes when the ball goes out of play after the time has passed
No change needed to the rules just enforce the existing one if obstruction when a player shields the ball out for goal kick by stopping the attacker getting at it., usually by putting their arms out