It seems that the problem isn't the lotting system, it's the party/alliance system. I would believe that the simple thing would be to make it so you cannot disband and alliance or party while there is a treasure pool. If you want to leave the party while there's a treasure pool, you can disband yourself, but the remaining people will still have the treasure pool.

In other words, just disable the ability to break an alliance or kick a player while there's a treasure pool (roughly a 5 minute wait time until your treasure pool clears naturally if you really need to kick someone, or you can all drop and regroup without them if you must lose them immediately). As a point, you might also want to consider that if someone wants to get an item in the treasure pool, a BLM can just warp other people away and leave the person who they want the item to go it, so the problem was never really solved anyway.

As a side note, can we get a /blockaid improvement for in party spells? There are times when I am intentionally trying to maintain my health in a yellow or red point to trigger gear effects and someone in my group will not notice who's health they're healing, just that someone is low. As a different example, I've had an occasional warp out of a zone before the treasure we were hunting was dispersed to me (because someone else hadn't passed and the BLM didn't notice there was still a Mavi Seal in the pool when they started sending everyone home for the night).

It would be helpful to have "/blockaid" stop outside assistance, and "/blockaid all" to block both inside and outside assitance.