If you're going to be putting down more than one seat deposit, more often than not they will not overlap, correct? For instance, while LSAC doesn't approve of having two out there at the same time, if you have to put one down by April 1 for school A, but you get pulled off the waitlist at school B in May, you can withdraw from school A and then put down a deposit at school B. In this scenario, you would have paid two seat deposits, but they would not be overlapping. It seems that their main goal is to avoid people putting down multiple deposits in April, then waiting until July to decide. And if you look at the links rosetta posted, it seems like they can take your offer of admission away.
It would be great if they would just adopt a standard date for notification and deposits.