Assume the Nu Lagoon begin operation with 50k next Friday, the btc price at $250 all the time,no new deposit and no withdraw, and the buy side and sell side always perfectly balance. I will submit the custodian fee grant requesting 2380NBT after the accounting report is published at 27-Mar, the last accounting day in month. If that grant passed at 6-Apr, 2380NBT will be added to the operation and it will show in the report at next accounting day,10-Apr.
Just like most previous LPC proposals which get paid after the LPC operation, the Nu Lagoon need shareholders keep to their promise. In your example, I think most pool participants will understand and tolerate the deviation(11 days). But if there is a strong sign that shareholders wouldn’t pass fee grant in future, the Nu Lagoon will cease operation, and fund will be returned back to participants. Participants will reserve the right to ask shareholder to pay those custodian fee in future.
Those custodian fee is belong to the Nu Lagoon participants, it should be distributed to them.
How much will be placed on exchanges won’t be fixed at 10%, instead it will be set according to how much is needed based on several factors, for example the total size of the fund, the trading volume on the exchange, how often the walls will be unbalanced. The base amount to which the fee rate should be applied is the total amount of funds.