There are several problems with the current caching logic in DataResourceWorker.renderDataResourceAsText(...).
Enabling the caching of rendered FTL-Templates from DataResources with the property disable.ftl.template.cache in content.properties enables a non-functioning block of code that handles the rendering of the cached template. And if it is deactivated (default), the FTL-Templates are still cached by the FreeMarkerWorker.
However the correct logic for caching and using the rendered FTL-Template is already implemented in the FreeMarkerWorker and controlled by an optional useCache parameter.
In addition there is an API call to DataResourceWorker.writeDataResourceText for non template content with a static "true" for useCache instead of using the given cache parameter value of the renderDataResourceAsText method itself, so even if the caller do not want to use caching at all, the non template text data is cached an FTL-Templates are cached also.
I will provide a patch for those two issues in the mentioned method.