OPC UA does not precisely have the distinction between the device read or cache read, but it is possible to specify a maximum age.
In QuickOPC, this is controlled by a parameter inside the UAReadParameters object. The property name is MaximumAge. By default, it reads from the cache, equaling to UAReadParameters.CacheMaximumAge. You can specify a number of milliseconds there.
UAReadParameters is part of UAReadArguments which is used in the most overloads of the various Read methods of EasyUAClient. There are also some overloads that take UAReadParameters directly, or can use the implicit conversion from a 'double' (number of milliseconds - the maximum age) to UAReadParameters.