poll-billing re-polls ports

I just discovered that the poll-billing script actually SNMP polls all the ports the bill. Wouldn't it be sufficient to just take the last sample from RRD (assuming it is within the polling period) rather than adding additional load to the devices and the Observium pollers? This is particularly bad for us because we are trying to create a bill that has 1300 ports in it, and that cannot be SNMP polled by a poll-billing within 5 minutes. If this were to just retrieve the last sample, then it would be done within seconds, which is what I had assumed it was doing.