Would take part in tournament based on just ended ladder season. 16 top players play for Ladder Cup, 1/8 of the Final, 1/4, 1/2, The Final. Such tournament could be as regular one, after each ended ladder season.
I like this idea, but to make it mandatory/automatic may not be realistic.
I'd say even doing a quick tournament for the top 4 ladder individuals would work, could do round robin style and most likely all four players are active enough to complete the games. Or could do top 8 single elimination style.
I agree that it shouldn't be mandatory one. And number 8 players looks more realistic than 16 because half of top 16 may be not interested to take part in the tournament, like some players don't take part in Supertour or previous tournaments. But I have a hope that this tournament can become very popular if it will be regular one. This way may expect for at least 8 players.