It can take over 10 match minutes for a substitution or change to take effect. Maybe Nordeus could look at speeding that up. .
Also, it would be great if you could see who is performing well during the game (ie a players rating going up or down during game). They could use the page where you can just view your team in game and it shows how many stars they have, why not show the current in game ranking. Means we can make tactical substitutions based on player form