I didn't playtest this, but I wonder if anyone thinks it could work well.
I think it might be best to play this variant in teams of two players each, plus one single player using the purple dice. So, play with a maximum of 7 players, of which one is the 'kicking player'. On his/her turn, the kicking player rolls and places all purple dice as normal, but
(A) he/she has all 10 dice to roll and only kicker dice, and
(B) kicker dice are not discarded after placement. The teams play as normal, also by still individually count their dice at the end of the round, but sharing their money pile.
Also a semi co-op vs kicker player variant might be possible. In this variant, one player is the kicking player and the other players work together to defeat him. The other players all roll and place their dice as normal, counting them individually at the end of the round, but they share their money pile. The kicking player rolls and places his/her dice and doesn't discard them. Additionally, for every kicker die placed, a die may be kicked out from EACH player, so not just one of them.
Example: Blue and Yellow respectively have 5 and 3 dice on the same casino. The kicking player now places 2 of his/her dice on the casino. He/she may now kick out 2 dice from each player instead of just one of them.