I think what they should do is after the 120 minutes, play another 30 minutes with the Golden Goal, and allow unlimited substitutions.
Don’t know about unlimited subs in extra time. I think teams at EURO 2020 get either5 or 6 subs.
I think they should get 2 more during extra time and maybe another one if it goes to a golden goal.
I remember WAY, WAY back in the day when there were no subs allowed. I know that was the rule during the 1966 World Cup.
The game had become so athletic, physical, and fast, quality suffered significantly in those days.
The solution be something other than PKs to determine the result of a match.
I would not be opposed to allowing starters to return to a match if it goes to a golden goal.