I've only started playing the past 2 days after putting my controller down in January.
I've played this gamemode since FUT first appeared in FIFA and its honestly getting boring now.
Some ideas of mine.
Bronze Silver and Gold tournaments.. bigger coin prizes for winning matches and final placing in tournaments with packs awarded for winning tournaments and leagues.
Div 1 players actually play Div 1/Div 2 players.
Div 2 plays Div 1/2/3.
Div 3 Plays Div 2/3/4
Bigger rewards for playing seasons based on your points tally overall and not just relegation or promotion.
Maybe you have to pay a salary each season per player based on a small percentage of how much the player cost to buy.
If you want a high rated squad you have to budget for it, maybe leading to a variety of squads you face.
Get rid off pace on chem cards and have the gameplay a similar pace as online seasons.
Ability to link players across leagues somehow, maybe have them play 50-100 to get 10 chemistry.
Longer injuries for players and show us what players are injury prone.
More variation on position changes to fill packs and the ability to customise formations on the FUT main menu with custom formation cards to fill packs.
Make it feel like a player manager mode.
Oh and layer the search for players by ping..50 m/s ping, then search 70 m/s ping, 100 ping etc to make the games fairer.