This is a real concern. Laws do exist to limit the time banks can hold deposits before making them available to write cheques on. The Expedited Funds Availability Act in the USA is an example of this that addresses a particular face of this form of moral hazard. I previously heard an anecdote of some bank(s) in the USA being found guilty, a number of decades ago, of wrongdoing by their sending payment (in the form of cheques via snail mail) from the furthest branch away from the destination in order to have access to the customer's money for a day or so more. The sheer volume of payments made this profitable. Insurance and other financial transactions are similar. Long processing times seem like a weak excuse.
I wrote that it may be time for Singapore to deal with the underlying problem. I said that the MAS should determine whether deferred payments may be considered reserve capital. (Yes, money could be used for other things, but I thought pointing to reserve capital as something tangible would make sense.) If the response turns out to be "no", incentives for such, arguably dishonest, corporate behaviour would be reduced.