What metrics or application types does your customer want to monitor? However I think it won't fit. Unless customer is running thick client applications in .NET/Java which can be instrumented. For retrieving just basic OS metric it's gonna be costly.
Depends on the use case. You can e.g. run the OneAgent in Cloud Infrastructure mode to get information about Resource Utilization and running processes.
For more advanced insights, a client analytics tool (e.g. nexthink) would be better suited.
It's just Oneagent for Windows, there is not a specific Oneagent for Windows 7. If you run it in infrastructure mode, it's limited for retrieving operating system metrics, plugins (out-of-box plugins and custom plugins developed using SDK). and basic process metrics. You don't get code level details, purepaths, services, etc...
In licensing terms it's counted with 0.3 ratio of a full stack agent. It's handy if you need to monitor just basic server functionality (OS) and monitoring running processes or some custom metrics. A good example is to have it on your database servers.