1- abandoned
Players abandon game before infinite waves to reduce king's workload. There must be some reduction of king stats when a team has abandoned players. Right now the king has disadvantage in a team receiving 4 waves vs 1 wave (3 quits). Nobody hangs around to watch their king die when quitting has an incentive, nobody cares about ratings and ranking either ;)

2- range units blocking summons
Before, the infinite waves were melee, the summoned units could attack the king, or reach the king at least. Right now the infinite waves are range, they block the summon units completely Further adding to this the limitations on number of summoned units, they become practically useless bunch of squishables who reach the king one by one and die before landing a hit. Reverting to melee waves can solve this one.

tldr:
I'd like to see some incentive for a player to stick around and watch a king die.
The summon units need to be relevant after the infinite wave stage. Bring back melee waves.