As we need to discuss some specific details about your integration, it would be better to do it privately, so, please send an email to build@smartthings.com with the info below.
This device usage will be household or a particular sector of the industry?
Also, what do you mean by the following?
“Reservation and notification settings”
On your side you will store the usage of the device to query its activity and present it in another way, for example, a chart?